Field Summary

Constructor Summary

Method Summary

Field Details

• MIN_VALUE

  @Nativepublic static final int MIN_VALUE

  A constant holding the minimum value anint canhave, -2³¹.

  See Also:

  • Constant Field Values

• MAX_VALUE

  @Nativepublic static final int MAX_VALUE

  A constant holding the maximum value anint canhave, 2³¹-1.

  See Also:

  • Constant Field Values

• TYPE

  public static final Class<Integer> TYPE

  TheClass instance representing the primitive typeint.

  Since:

  1.1

• SIZE

  @Nativepublic static final int SIZE

  The number of bits used to represent anint value in two'scomplement binary form.

  Since:

  1.5

  See Also:

  • Constant Field Values

• BYTES

  public static final int BYTES

  The number of bytes used to represent anint value in two'scomplement binary form.

  Since:

  1.8

  See Also:

  • Constant Field Values

Constructor Details

• Integer

  @Deprecated(since="9")public Integer(int value)

  Deprecated.

  It is rarely appropriate to use this constructor. The static factoryvalueOf(int) is generally a better choice, as it islikely to yield significantly better space and time performance.

  Constructs a newly allocatedInteger object thatrepresents the specifiedint value.

  Parameters:

  value - the value to be represented by theInteger object.

• Integer

  @Deprecated(since="9")public Integer(String s) throwsNumberFormatException

  Deprecated.

  It is rarely appropriate to use this constructor.UseparseInt(String) to convert a string to aint primitive, or usevalueOf(String)to convert a string to anInteger object.

  Constructs a newly allocatedInteger object thatrepresents theint value indicated by theString parameter. The string is converted to anint value in exactly the manner used by theparseInt method for radix 10.

  Parameters:

  s - theString to be converted to anInteger.

  Throws:

  NumberFormatException - if theString does not contain a parsable integer.

Method Details

• toString

  public static String toString(int i, int radix)

  Returns a string representation of the first argument in theradix specified by the second argument.

  If the radix is smaller thanCharacter.MIN_RADIXor larger thanCharacter.MAX_RADIX, then the radix10 is used instead.

  If the first argument is negative, the first element of theresult is the ASCII minus character'-'('\u002D'). If the first argument is notnegative, no sign character appears in the result.

  The remaining characters of the result represent the magnitudeof the first argument. If the magnitude is zero, it isrepresented by a single zero character'0'('\u0030'); otherwise, the first character ofthe representation of the magnitude will not be the zerocharacter. The following ASCII characters are used as digits:

  0123456789abcdefghijklmnopqrstuvwxyz

  These are'\u0030' through'\u0039' and'\u0061' through'\u007A'. Ifradix isN, then the firstN of these charactersare used as radix-N digits in the order shown. Thus,the digits for hexadecimal (radix 16) are0123456789abcdef. If uppercase letters aredesired, theString.toUpperCase() method maybe called on the result:

  Integer.toString(n, 16).toUpperCase()

  Parameters:

  i - an integer to be converted to a string.

  radix - the radix to use in the string representation.

  Returns:

  a string representation of the argument in the specified radix.

  See Also:

  • Character.MAX_RADIX
  • Character.MIN_RADIX

• toUnsignedString

  public static String toUnsignedString(int i, int radix)

  Returns a string representation of the first argument as anunsigned integer value in the radix specified by the secondargument.

  If the radix is smaller thanCharacter.MIN_RADIXor larger thanCharacter.MAX_RADIX, then the radix10 is used instead.

  Note that since the first argument is treated as an unsignedvalue, no leading sign character is printed.

  If the magnitude is zero, it is represented by a single zerocharacter'0' ('\u0030'); otherwise,the first character of the representation of the magnitude willnot be the zero character.

  The behavior of radixes and the characters used as digitsare the same astoString.

  Parameters:

  i - an integer to be converted to an unsigned string.

  radix - the radix to use in the string representation.

  Returns:

  an unsigned string representation of the argument in the specified radix.

  Since:

  1.8

  See Also:

  • toString(int, int)

• toHexString

  public static String toHexString(int i)

  Returns a string representation of the integer argument as anunsigned integer in base 16.

  The unsigned integer value is the argument plus 2³²if the argument is negative; otherwise, it is equal to theargument. This value is converted to a string of ASCII digitsin hexadecimal (base 16) with no extra leading0s.

  The value of the argument can be recovered from the returnedstrings by callingInteger.parseUnsignedInt(s, 16).

  If the unsigned magnitude is zero, it is represented by asingle zero character'0' ('\u0030');otherwise, the first character of the representation of theunsigned magnitude will not be the zero character. Thefollowing characters are used as hexadecimal digits:

  0123456789abcdef

  These are the characters'\u0030' through'\u0039' and'\u0061' through'\u0066'. If uppercase letters aredesired, theString.toUpperCase() method maybe called on the result:

  Integer.toHexString(n).toUpperCase()

  API Note:

  TheHexFormat class provides formatting and parsingof byte arrays and primitives to return a string or adding to anAppendable.HexFormat formats and parses uppercase or lowercase hexadecimal characters,with leading zeros and for byte arrays includes for each bytea delimiter, prefix, and suffix.

  Parameters:

  i - an integer to be converted to a string.

  Returns:

  the string representation of the unsigned integer value represented by the argument in hexadecimal (base 16).

  Since:

  1.0.2

  See Also:

  • HexFormat
  • parseUnsignedInt(String, int)
  • toUnsignedString(int, int)

• toOctalString

  public static String toOctalString(int i)

  Returns a string representation of the integer argument as anunsigned integer in base 8.

  The unsigned integer value is the argument plus 2³²if the argument is negative; otherwise, it is equal to theargument. This value is converted to a string of ASCII digitsin octal (base 8) with no extra leading0s.

  The value of the argument can be recovered from the returnedstrings by callingInteger.parseUnsignedInt(s, 8).

  If the unsigned magnitude is zero, it is represented by asingle zero character'0' ('\u0030');otherwise, the first character of the representation of theunsigned magnitude will not be the zero character. Thefollowing characters are used as octal digits:

  01234567

  These are the characters'\u0030' through'\u0037'.

  Parameters:

  i - an integer to be converted to a string.

  Returns:

  the string representation of the unsigned integer value represented by the argument in octal (base 8).

  Since:

  1.0.2

  See Also:

  • parseUnsignedInt(String, int)
  • toUnsignedString(int, int)

• toBinaryString

  public static String toBinaryString(int i)

  Returns a string representation of the integer argument as anunsigned integer in base 2.

  The unsigned integer value is the argument plus 2³²if the argument is negative; otherwise it is equal to theargument. This value is converted to a string of ASCII digitsin binary (base 2) with no extra leading0s.

  The value of the argument can be recovered from the returnedstrings by callingInteger.parseUnsignedInt(s, 2).

  If the unsigned magnitude is zero, it is represented by asingle zero character'0' ('\u0030');otherwise, the first character of the representation of theunsigned magnitude will not be the zero character. Thecharacters'0' ('\u0030') and'1' ('\u0031') are used as binary digits.

  Parameters:

  i - an integer to be converted to a string.

  Returns:

  the string representation of the unsigned integer value represented by the argument in binary (base 2).

  Since:

  1.0.2

  See Also:

  • parseUnsignedInt(String, int)
  • toUnsignedString(int, int)

• toString

  public static String toString(int i)

  Returns aString object representing thespecified integer. The argument is converted to signed decimalrepresentation and returned as a string, exactly as if theargument and radix 10 were given as arguments to thetoString(int, int) method.

  Parameters:

  i - an integer to be converted.

  Returns:

  a string representation of the argument in base 10.

• toUnsignedString

  public static String toUnsignedString(int i)

  Returns a string representation of the argument as an unsigneddecimal value.The argument is converted to unsigned decimal representationand returned as a string exactly as if the argument and radix10 were given as arguments to thetoUnsignedString(int, int) method.

  Parameters:

  i - an integer to be converted to an unsigned string.

  Returns:

  an unsigned string representation of the argument.

  Since:

  1.8

  See Also:

  • toUnsignedString(int, int)

• parseInt

  public static int parseInt(String s, int radix) throwsNumberFormatException

  Parses the string argument as a signed integer in the radixspecified by the second argument. The characters in the stringmust all be digits of the specified radix (as determined bywhetherCharacter.digit(char, int) returns anonnegative value), except that the first character may be anASCII minus sign'-' ('\u002D') toindicate a negative value or an ASCII plus sign'+'('\u002B') to indicate a positive value. Theresulting integer value is returned.

  An exception of typeNumberFormatException isthrown if any of the following situations occurs:

  • The first argument isnull or is a string oflength zero.
  • The radix is either smaller thanCharacter.MIN_RADIX orlarger thanCharacter.MAX_RADIX.
  • Any character of the string is not a digit of the specifiedradix, except that the first character may be a minus sign'-' ('\u002D') or plus sign'+' ('\u002B') provided that thestring is longer than length 1.
  • The value represented by the string is not a value of typeint.

  Examples:

  parseInt("0", 10) returns 0parseInt("473", 10) returns 473parseInt("+42", 10) returns 42parseInt("-0", 10) returns 0parseInt("-FF", 16) returns -255parseInt("1100110", 2) returns 102parseInt("2147483647", 10) returns 2147483647parseInt("-2147483648", 10) returns -2147483648parseInt("2147483648", 10) throws a NumberFormatExceptionparseInt("99", 8) throws a NumberFormatExceptionparseInt("Kona", 10) throws a NumberFormatExceptionparseInt("Kona", 27) returns 411787

  Parameters:

  s - theString containing the integer representation to be parsed

  radix - the radix to be used while parsings.

  Returns:

  the integer represented by the string argument in the specified radix.

  Throws:

  NumberFormatException - if theString does not contain a parsableint.

• parseInt

  public static int parseInt(CharSequence s, int beginIndex, int endIndex, int radix) throwsNumberFormatException

  Parses theCharSequence argument as a signedint in thespecifiedradix, beginning at the specifiedbeginIndexand extending toendIndex - 1.

  The method does not take steps to guard against theCharSequence being mutated while parsing.

  Parameters:

  s - theCharSequence containing theint representation to be parsed

  beginIndex - the beginning index, inclusive.

  endIndex - the ending index, exclusive.

  radix - the radix to be used while parsings.

  Returns:

  the signedint represented by the subsequence in the specified radix.

  Throws:

  NullPointerException - ifs is null.

  IndexOutOfBoundsException - ifbeginIndex is negative, or ifbeginIndex is greater thanendIndex or ifendIndex is greater thans.length().

  NumberFormatException - if theCharSequence does not contain a parsableint in the specifiedradix, or ifradix is either smaller thanCharacter.MIN_RADIX or larger thanCharacter.MAX_RADIX.

  Since:

  9

• parseInt

  public static int parseInt(String s) throwsNumberFormatException

  Parses the string argument as a signed decimal integer. Thecharacters in the string must all be decimal digits, exceptthat the first character may be an ASCII minus sign'-'('\u002D') to indicate a negative value or anASCII plus sign'+' ('\u002B') toindicate a positive value. The resulting integer value isreturned, exactly as if the argument and the radix 10 weregiven as arguments to theparseInt(java.lang.String, int) method.

  Parameters:

  s - aString containing theint representation to be parsed

  Returns:

  the integer value represented by the argument in decimal.

  Throws:

  NumberFormatException - if the string does not contain a parsable integer.

• parseUnsignedInt

  public static int parseUnsignedInt(String s, int radix) throwsNumberFormatException

  Parses the string argument as an unsigned integer in the radixspecified by the second argument. An unsigned integer maps thevalues usually associated with negative numbers to positivenumbers larger thanMAX_VALUE.The characters in the string must all be digits of thespecified radix (as determined by whetherCharacter.digit(char, int) returns a nonnegativevalue), except that the first character may be an ASCII plussign'+' ('\u002B'). The resultinginteger value is returned.

  An exception of typeNumberFormatException isthrown if any of the following situations occurs:

  • The first argument isnull or is a string oflength zero.
  • The radix is either smaller thanCharacter.MIN_RADIX orlarger thanCharacter.MAX_RADIX.
  • Any character of the string is not a digit of the specifiedradix, except that the first character may be a plus sign'+' ('\u002B') provided that thestring is longer than length 1.
  • The value represented by the string is larger than thelargest unsignedint, 2³²-1.

  Parameters:

  s - theString containing the unsigned integer representation to be parsed

  radix - the radix to be used while parsings.

  Returns:

  the integer represented by the string argument in the specified radix.

  Throws:

  NumberFormatException - if theString does not contain a parsableint.

  Since:

  1.8

• parseUnsignedInt

  public static int parseUnsignedInt(CharSequence s, int beginIndex, int endIndex, int radix) throwsNumberFormatException

  Parses theCharSequence argument as an unsignedint inthe specifiedradix, beginning at the specifiedbeginIndex and extending toendIndex - 1.

  The method does not take steps to guard against theCharSequence being mutated while parsing.

  Parameters:

  s - theCharSequence containing the unsignedint representation to be parsed

  beginIndex - the beginning index, inclusive.

  endIndex - the ending index, exclusive.

  radix - the radix to be used while parsings.

  Returns:

  the unsignedint represented by the subsequence in the specified radix.

  Throws:

  NullPointerException - ifs is null.

  IndexOutOfBoundsException - ifbeginIndex is negative, or ifbeginIndex is greater thanendIndex or ifendIndex is greater thans.length().

  NumberFormatException - if theCharSequence does not contain a parsable unsignedint in the specifiedradix, or ifradix is either smaller thanCharacter.MIN_RADIX or larger thanCharacter.MAX_RADIX.

  Since:

  9

• parseUnsignedInt

  public static int parseUnsignedInt(String s) throwsNumberFormatException

  Parses the string argument as an unsigned decimal integer. Thecharacters in the string must all be decimal digits, exceptthat the first character may be an ASCII plus sign'+' ('\u002B'). The resulting integer valueis returned, exactly as if the argument and the radix 10 weregiven as arguments to theparseUnsignedInt(java.lang.String, int) method.

  Parameters:

  s - aString containing the unsignedint representation to be parsed

  Returns:

  the unsigned integer value represented by the argument in decimal.

  Throws:

  NumberFormatException - if the string does not contain a parsable unsigned integer.

  Since:

  1.8

• valueOf

  public static Integer valueOf(String s, int radix) throwsNumberFormatException

  Returns anInteger object holding the valueextracted from the specifiedString when parsedwith the radix given by the second argument. The first argumentis interpreted as representing a signed integer in the radixspecified by the second argument, exactly as if the argumentswere given to theparseInt(java.lang.String, int)method. The result is anInteger object thatrepresents the integer value specified by the string.

  In other words, this method returns anIntegerobject equal to the value of:

  Integer.valueOf(Integer.parseInt(s, radix))

  Parameters:

  s - the string to be parsed.

  radix - the radix to be used in interpretings

  Returns:

  anInteger object holding the value represented by the string argument in the specified radix.

  Throws:

  NumberFormatException - if theString does not contain a parsableint.

• valueOf

  public static Integer valueOf(String s) throwsNumberFormatException

  Returns anInteger object holding thevalue of the specifiedString. The argument isinterpreted as representing a signed decimal integer, exactlyas if the argument were given to theparseInt(java.lang.String) method. The result is anInteger object that represents the integer valuespecified by the string.

  In other words, this method returns anIntegerobject equal to the value of:

  Integer.valueOf(Integer.parseInt(s))

  Parameters:

  s - the string to be parsed.

  Returns:

  anInteger object holding the value represented by the string argument.

  Throws:

  NumberFormatException - if the string cannot be parsed as an integer.

• valueOf

  public static Integer valueOf(int i)

  Returns anInteger instance representing the specifiedint value. If a newInteger instance is notrequired, this method should generally be used in preference tothe constructorInteger(int), as this method is likelyto yield significantly better space and time performance bycaching frequently requested values.This method will always cache values in the range -128 to 127,inclusive, and may cache other values outside of this range.

  Parameters:

  i - anint value.

  Returns:

  anInteger instance representingi.

  Since:

  1.5

• byteValue

  public byte byteValue()

  Returns the value of thisInteger as abyteafter a narrowing primitive conversion.

  Overrides:

  byteValue in class Number

  Returns:

  the numeric value represented by this object after conversion to typebyte.

  SeeJava Language Specification:

  5.1.3 Narrowing Primitive Conversion
  

• shortValue

  public short shortValue()

  Returns the value of thisInteger as ashortafter a narrowing primitive conversion.

  Overrides:

  shortValue in class Number

  Returns:

  the numeric value represented by this object after conversion to typeshort.

  SeeJava Language Specification:

  5.1.3 Narrowing Primitive Conversion
  

• intValue

  public int intValue()

  Returns the value of thisInteger as anint.

  Specified by:

  intValue in class Number

  Returns:

  the numeric value represented by this object after conversion to typeint.

• longValue

  public long longValue()

  Returns the value of thisInteger as alongafter a widening primitive conversion.

  Specified by:

  longValue in class Number

  Returns:

  the numeric value represented by this object after conversion to typelong.

  SeeJava Language Specification:

  5.1.2 Widening Primitive Conversion
  

  See Also:

  • toUnsignedLong(int)

• floatValue

  public float floatValue()

  Returns the value of thisInteger as afloatafter a widening primitive conversion.

  Specified by:

  floatValue in class Number

  Returns:

  the numeric value represented by this object after conversion to typefloat.

  SeeJava Language Specification:

  5.1.2 Widening Primitive Conversion
  

• doubleValue

  public double doubleValue()

  Returns the value of thisInteger as adoubleafter a widening primitive conversion.

  Specified by:

  doubleValue in class Number

  Returns:

  the numeric value represented by this object after conversion to typedouble.

  SeeJava Language Specification:

  5.1.2 Widening Primitive Conversion
  

• toString

  public String toString()

  Returns aString object representing thisInteger's value. The value is converted to signeddecimal representation and returned as a string, exactly as ifthe integer value were given as an argument to thetoString(int) method.

  Overrides:

  toString in class Object

  Returns:

  a string representation of the value of this object in base 10.

• hashCode

  public int hashCode()

  Returns a hash code for thisInteger.

  Overrides:

  hashCode in class Object

  Returns:

  a hash code value for this object, equal to the primitiveint value represented by thisInteger object.

  See Also:

  • Object.equals(java.lang.Object)
  • System.identityHashCode(Object)

• hashCode

  public static int hashCode(int value)

  Returns a hash code for anint value; compatible withInteger.hashCode().

  Parameters:

  value - the value to hash

  Returns:

  a hash code value for anint value.

  Since:

  1.8

• equals

  public boolean equals(Object obj)

  Compares this object to the specified object. The result istrue if and only if the argument is notnull and is anInteger object thatcontains the sameint value as this object.

  Overrides:

  equals in class Object

  Parameters:

  obj - the object to compare with.

  Returns:

  true if the objects are the same;false otherwise.

  See Also:

  • Object.hashCode()
  • HashMap

• getInteger

  public static Integer getInteger(String nm)

  Determines the integer value of the system property with thespecified name.

  The first argument is treated as the name of a systemproperty. System properties are accessible through theSystem.getProperty(java.lang.String) method. Thestring value of this property is then interpreted as an integervalue using the grammar supported bydecode andanInteger object representing this value is returned.

  If there is no property with the specified name, if thespecified name is empty ornull, or if the propertydoes not have the correct numeric format, thennull isreturned.

  In other words, this method returns anIntegerobject equal to the value of:

  getInteger(nm, null)

  Parameters:

  nm - property name.

  Returns:

  theInteger value of the property.

  See Also:

  • System.getProperty(java.lang.String)
  • System.getProperty(java.lang.String, java.lang.String)

• getInteger

  public static Integer getInteger(String nm, int val)

  Determines the integer value of the system property with thespecified name.

  The first argument is treated as the name of a systemproperty. System properties are accessible through theSystem.getProperty(java.lang.String) method. Thestring value of this property is then interpreted as an integervalue using the grammar supported bydecode andanInteger object representing this value is returned.

  The second argument is the default value. AnInteger objectthat represents the value of the second argument is returned if thereis no property of the specified name, if the property does not havethe correct numeric format, or if the specified name is empty ornull.

  In other words, this method returns anInteger objectequal to the value of:

  getInteger(nm, Integer.valueOf(val))

  but in practice it may be implemented in a manner such as:

  Integer result = getInteger(nm, null);return (result == null) ? Integer.valueOf(val) : result;

  to avoid the unnecessary allocation of anIntegerobject when the default value is not needed.

  Parameters:

  nm - property name.

  val - default value.

  Returns:

  theInteger value of the property.

  See Also:

  • System.getProperty(java.lang.String)
  • System.getProperty(java.lang.String, java.lang.String)

• getInteger

  public static Integer getInteger(String nm,Integer val)

  Returns the integer value of the system property with thespecified name. The first argument is treated as the name of asystem property. System properties are accessible through theSystem.getProperty(java.lang.String) method.The string value of this property is then interpreted as aninteger value, as per thedecode method,and anInteger object representing this value isreturned; in summary:

  • If the property value begins with the two ASCII characters0x or the ASCII character#, not followed by a minus sign, then the rest of it is parsed as a hexadecimal integer exactly as by the methodvalueOf(java.lang.String, int) with radix 16.
  • If the property value begins with the ASCII character0 followed by another character, it is parsed as an octal integer exactly as by the methodvalueOf(java.lang.String, int) with radix 8.
  • Otherwise, the property value is parsed as a decimal integerexactly as by the methodvalueOf(java.lang.String, int)with radix 10.

  The second argument is the default value. The default value isreturned if there is no property of the specified name, if theproperty does not have the correct numeric format, or if thespecified name is empty ornull.

  Parameters:

  nm - property name.

  val - default value.

  Returns:

  theInteger value of the property.

  See Also:

  • System.getProperty(java.lang.String)
  • System.getProperty(java.lang.String, java.lang.String)

• decode

  public static Integer decode(String nm) throwsNumberFormatException

  Decodes aString into anInteger.Accepts decimal, hexadecimal, and octal numbers givenby the following grammar:

  DecodableString:

  Sign_opt DecimalNumeral

  Sign_opt0xHexDigits

  Sign_opt0XHexDigits

  Sign_opt#HexDigits

  Sign_opt0OctalDigits

  Sign:

  -

  +

  DecimalNumeral,HexDigits, andOctalDigitsare as defined in section3.10.1 ofThe Java Language Specification,except that underscores are not accepted between digits.

  The sequence of characters following an optionalsign and/or radix specifier ("0x", "0X","#", or leading zero) is parsed as by theInteger.parseInt method with the indicated radix (10, 16, or8). This sequence of characters must represent a positivevalue or aNumberFormatException will be thrown. Theresult is negated if first character of the specifiedString is the minus sign. No whitespace characters arepermitted in theString.

  Parameters:

  nm - theString to decode.

  Returns:

  anInteger object holding theint value represented bynm

  Throws:

  NumberFormatException - if theString does not contain a parsable integer.

  See Also:

  • parseInt(java.lang.String, int)

• compareTo

  public int compareTo(Integer anotherInteger)

  Compares twoInteger objects numerically.

  Specified by:

  compareTo in interface Comparable<Integer>

  Parameters:

  anotherInteger - theInteger to be compared.

  Returns:

  the value0 if thisInteger is equal to the argumentInteger; a value less than0 if thisInteger is numerically less than the argumentInteger; and a value greater than0 if thisInteger is numerically greater than the argumentInteger (signed comparison).

  Since:

  1.2

• compare

  public static int compare(int x, int y)

  Compares twoint values numerically.The value returned is identical to what would be returned by:

     Integer.valueOf(x).compareTo(Integer.valueOf(y))

  Parameters:

  x - the firstint to compare

  y - the secondint to compare

  Returns:

  the value0 ifx == y; a value less than0 ifx < y; and a value greater than0 ifx > y

  Since:

  1.7

• compareUnsigned

  public static int compareUnsigned(int x, int y)

  Compares twoint values numerically treating the valuesas unsigned.

  Parameters:

  x - the firstint to compare

  y - the secondint to compare

  Returns:

  the value0 ifx == y; a value less than0 ifx < y as unsigned values; and a value greater than0 ifx > y as unsigned values

  Since:

  1.8

• toUnsignedLong

  public static long toUnsignedLong(int x)

  Converts the argument to along by an unsignedconversion. In an unsigned conversion to along, thehigh-order 32 bits of thelong are zero and thelow-order 32 bits are equal to the bits of the integerargument.Consequently, zero and positiveint values are mappedto a numerically equallong value and negativeint values are mapped to along value equal to theinput plus 2³².

  Parameters:

  x - the value to convert to an unsignedlong

  Returns:

  the argument converted tolong by an unsigned conversion

  Since:

  1.8

• divideUnsigned

  public static int divideUnsigned(int dividend, int divisor)

  Returns the unsigned quotient of dividing the first argument bythe second where each argument and the result is interpreted asan unsigned value.

  Note that in two's complement arithmetic, the three otherbasic arithmetic operations of add, subtract, and multiply arebit-wise identical if the two operands are regarded as bothbeing signed or both being unsigned. Therefore separateaddUnsigned, etc. methods are not provided.

  Parameters:

  dividend - the value to be divided

  divisor - the value doing the dividing

  Returns:

  the unsigned quotient of the first argument divided bythe second argument

  Since:

  1.8

  See Also:

  • remainderUnsigned(int, int)

• remainderUnsigned

  public static int remainderUnsigned(int dividend, int divisor)

  Returns the unsigned remainder from dividing the first argumentby the second where each argument and the result is interpretedas an unsigned value.

  Parameters:

  dividend - the value to be divided

  divisor - the value doing the dividing

  Returns:

  the unsigned remainder of the first argument divided bythe second argument

  Since:

  1.8

  See Also:

  • divideUnsigned(int, int)

• highestOneBit

  public static int highestOneBit(int i)

  Returns anint value with at most a single one-bit, in theposition of the highest-order ("leftmost") one-bit in the specifiedint value. Returns zero if the specified value has noone-bits in its two's complement binary representation, that is, if itis equal to zero.

  Parameters:

  i - the value whose highest one bit is to be computed

  Returns:

  anint value with a single one-bit, in the position of the highest-order one-bit in the specified value, or zero if the specified value is itself equal to zero.

  Since:

  1.5

• lowestOneBit

  public static int lowestOneBit(int i)

  Returns anint value with at most a single one-bit, in theposition of the lowest-order ("rightmost") one-bit in the specifiedint value. Returns zero if the specified value has noone-bits in its two's complement binary representation, that is, if itis equal to zero.

  Parameters:

  i - the value whose lowest one bit is to be computed

  Returns:

  anint value with a single one-bit, in the position of the lowest-order one-bit in the specified value, or zero if the specified value is itself equal to zero.

  Since:

  1.5

• numberOfLeadingZeros

  public static int numberOfLeadingZeros(int i)

  Returns the number of zero bits preceding the highest-order("leftmost") one-bit in the two's complement binary representationof the specifiedint value. Returns 32 if thespecified value has no one-bits in its two's complement representation,in other words if it is equal to zero.

  Note that this method is closely related to the logarithm base 2.For all positiveint values x:

  • floor(log₂(x)) =31 - numberOfLeadingZeros(x)
  • ceil(log₂(x)) =32 - numberOfLeadingZeros(x - 1)

  Parameters:

  i - the value whose number of leading zeros is to be computed

  Returns:

  the number of zero bits preceding the highest-order ("leftmost") one-bit in the two's complement binary representation of the specifiedint value, or 32 if the value is equal to zero.

  Since:

  1.5

• numberOfTrailingZeros

  public static int numberOfTrailingZeros(int i)

  Returns the number of zero bits following the lowest-order ("rightmost")one-bit in the two's complement binary representation of the specifiedint value. Returns 32 if the specified value has noone-bits in its two's complement representation, in other words if it isequal to zero.

  Parameters:

  i - the value whose number of trailing zeros is to be computed

  Returns:

  the number of zero bits following the lowest-order ("rightmost") one-bit in the two's complement binary representation of the specifiedint value, or 32 if the value is equal to zero.

  Since:

  1.5

• bitCount

  public static int bitCount(int i)

  Returns the number of one-bits in the two's complement binaryrepresentation of the specifiedint value. This function issometimes referred to as thepopulation count.

  Parameters:

  i - the value whose bits are to be counted

  Returns:

  the number of one-bits in the two's complement binary representation of the specifiedint value.

  Since:

  1.5

• rotateLeft

  public static int rotateLeft(int i, int distance)

  Returns the value obtained by rotating the two's complement binaryrepresentation of the specifiedint value left by thespecified number of bits. (Bits shifted out of the left hand, orhigh-order, side reenter on the right, or low-order.)

  Note that left rotation with a negative distance is equivalent toright rotation:rotateLeft(val, -distance) == rotateRight(val,distance). Note also that rotation by any multiple of 32 is ano-op, so all but the last five bits of the rotation distance can beignored, even if the distance is negative:rotateLeft(val,distance) == rotateLeft(val, distance & 0x1F).

  Parameters:

  i - the value whose bits are to be rotated left

  distance - the number of bit positions to rotate left

  Returns:

  the value obtained by rotating the two's complement binary representation of the specifiedint value left by the specified number of bits.

  Since:

  1.5

• rotateRight

  public static int rotateRight(int i, int distance)

  Returns the value obtained by rotating the two's complement binaryrepresentation of the specifiedint value right by thespecified number of bits. (Bits shifted out of the right hand, orlow-order, side reenter on the left, or high-order.)

  Note that right rotation with a negative distance is equivalent toleft rotation:rotateRight(val, -distance) == rotateLeft(val,distance). Note also that rotation by any multiple of 32 is ano-op, so all but the last five bits of the rotation distance can beignored, even if the distance is negative:rotateRight(val,distance) == rotateRight(val, distance & 0x1F).

  Parameters:

  i - the value whose bits are to be rotated right

  distance - the number of bit positions to rotate right

  Returns:

  the value obtained by rotating the two's complement binary representation of the specifiedint value right by the specified number of bits.

  Since:

  1.5

• reverse

  public static int reverse(int i)

  Returns the value obtained by reversing the order of the bits in thetwo's complement binary representation of the specifiedintvalue.

  Parameters:

  i - the value to be reversed

  Returns:

  the value obtained by reversing order of the bits in the specifiedint value.

  Since:

  1.5

• compress

  public static int compress(int i, int mask)

  Returns the value obtained by compressing the bits of thespecifiedint value,i, in accordance withthe specified bit mask.

  For each one-bit valuemb of the mask, from leastsignificant to most significant, the bit value ofi atthe same bit location asmb is assigned to the compressedvalue contiguously starting from the least significant bit location.All the upper remaining bits of the compressed value are setto zero.

  API Note:

  Consider the simple case of compressing the digits of a hexadecimalvalue:

  Copy

  // Compressing drink to foodcompress(0xCAFEBABE, 0xFF00FFF0) == 0xCABAB

  Starting from the least significant hexadecimal digit at position 0from the right, the mask0xFF00FFF0 selects hexadecimal digitsat positions 1, 2, 3, 6 and 7 of0xCAFEBABE. The selected digitsoccur in the resulting compressed value contiguously from digit position0 in the same order.

  The following identities all returntrue and are helpful tounderstand the behaviour ofcompress:

  Copy

  // Returns 1 if the bit at position n is onecompress(x, 1 << n) == (x >> n & 1)// Logical shift rightcompress(x, -1 << n) == x >>> n// Any bits not covered by the mask are ignoredcompress(x, m) == compress(x & m, m)// Compressing a value by itselfcompress(m, m) == (m == -1 || m == 0) ? m : (1 << bitCount(m)) - 1// Expanding then compressing with the same maskcompress(expand(x, m), m) == x & compress(m, m)

  The Sheep And Goats (SAG) operation (see Hacker's Delight, Second Edition, section 7.7)can be implemented as follows:

  Copy

  int compressLeft(int i, int mask) {    // This implementation follows the description in Hacker's Delight which    // is informative. A more optimal implementation is:    //   Integer.compress(i, mask) << -Integer.bitCount(mask)    return Integer.reverse(        Integer.compress(Integer.reverse(i), Integer.reverse(mask)));}int sag(int i, int mask) {    return compressLeft(i, mask) | Integer.compress(i, ~mask);}// Separate the sheep from the goatssag(0xCAFEBABE, 0xFF00FFF0) == 0xCABABFEE

  Parameters:

  i - the value whose bits are to be compressed

  mask - the bit mask

  Returns:

  the compressed value

  Since:

  19

  See Also:

  • expand(int, int)

• expand

  public static int expand(int i, int mask)

  Returns the value obtained by expanding the bits of thespecifiedint value,i, in accordance withthe specified bit mask.

  For each one-bit valuemb of the mask, from leastsignificant to most significant, the next contiguous bit valueofi starting at the least significant bit is assignedto the expanded value at the same bit location asmb.All other remaining bits of the expanded value are set to zero.

  API Note:

  Consider the simple case of expanding the digits of a hexadecimalvalue:

  Copy

  expand(0x0000CABAB, 0xFF00FFF0) == 0xCA00BAB0

  Starting from the least significant hexadecimal digit at position 0from the right, the mask0xFF00FFF0 selects the first fivehexadecimal digits of0x0000CABAB. The selected digits occurin the resulting expanded value in order at positions 1, 2, 3, 6, and 7.

  The following identities all returntrue and are helpful tounderstand the behaviour ofexpand:

  Copy

  // Logically shift right the bit at position 0expand(x, 1 << n) == (x & 1) << n// Logically shift rightexpand(x, -1 << n) == x << n// Expanding all bits returns the maskexpand(-1, m) == m// Any bits not covered by the mask are ignoredexpand(x, m) == expand(x, m) & m// Compressing then expanding with the same maskexpand(compress(x, m), m) == x & m

  The select operation for determining the position of the one-bit withindexn in aint value can be implemented as follows:

  Copy

  int select(int i, int n) {    // the one-bit in i (the mask) with index n    int nthBit = Integer.expand(1 << n, i);    // the bit position of the one-bit with index n    return Integer.numberOfTrailingZeros(nthBit);}// The one-bit with index 0 is at bit position 1select(0b10101010_10101010, 0) == 1// The one-bit with index 3 is at bit position 7select(0b10101010_10101010, 3) == 7

  Parameters:

  i - the value whose bits are to be expanded

  mask - the bit mask

  Returns:

  the expanded value

  Since:

  19

  See Also:

  • compress(int, int)

• signum

  public static int signum(int i)

  Returns the signum function of the specifiedint value. (Thereturn value is -1 if the specified value is negative; 0 if thespecified value is zero; and 1 if the specified value is positive.)

  Parameters:

  i - the value whose signum is to be computed

  Returns:

  the signum function of the specifiedint value.

  Since:

  1.5

• reverseBytes

  public static int reverseBytes(int i)

  Returns the value obtained by reversing the order of the bytes in thetwo's complement representation of the specifiedint value.

  Parameters:

  i - the value whose bytes are to be reversed

  Returns:

  the value obtained by reversing the bytes in the specifiedint value.

  Since:

  1.5

• sum

  public static int sum(int a, int b)

  Adds two integers together as per the + operator.

  Parameters:

  a - the first operand

  b - the second operand

  Returns:

  the sum ofa andb

  Since:

  1.8

  See Also:

  • BinaryOperator

• max

  public static int max(int a, int b)

  Returns the greater of twoint valuesas if by callingMath.max.

  Parameters:

  a - the first operand

  b - the second operand

  Returns:

  the greater ofa andb

  Since:

  1.8

  See Also:

  • BinaryOperator

• min

  public static int min(int a, int b)

  Returns the smaller of twoint valuesas if by callingMath.min.

  Parameters:

  a - the first operand

  b - the second operand

  Returns:

  the smaller ofa andb

  Since:

  1.8

  See Also:

  • BinaryOperator

• describeConstable

  public Optional<Integer> describeConstable()

  Returns anOptional containing the nominal descriptor for thisinstance, which is the instance itself.

  Specified by:

  describeConstable in interface Constable

  Returns:

  anOptional describing theInteger instance

  Since:

  12

• resolveConstantDesc

  public Integer resolveConstantDesc(MethodHandles.Lookup lookup)

  Resolves this instance as aConstantDesc, the result of which isthe instance itself.

  Specified by:

  resolveConstantDesc in interface ConstantDesc

  Parameters:

  lookup - ignored

  Returns:

  theInteger instance

  Since:

  12