JavaStrings

Java Strings

Strings are used for storing text.

AString variable contains a collection of characters surrounded by double quotes (""):

String greeting = "Hello";

String Length

A String in Java is actually an object, which means it containsmethods that can perform certain operations on strings.

For example, you can find the length of a string with thelength() method:

String txt = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";System.out.println("The length of the txt string is: " + txt.length());

More String Methods

There are many string methods available in Java.

For example:

• ThetoUpperCase() method converts a string toupper case letters.
• ThetoLowerCase() method converts a string tolower case letters.

String txt = "Hello World";System.out.println(txt.toUpperCase());   // Outputs "HELLO WORLD"System.out.println(txt.toLowerCase());   // Outputs "hello world"

Finding a Character in a String

TheindexOf() method returns theindex (the position) of the first occurrence of a specified text in a string (including whitespace):

String txt = "Please locate where 'locate' occurs!";System.out.println(txt.indexOf("locate")); // Outputs 7

You can use thecharAt() method to access a character at a specific position in a string:

String txt = "Hello";System.out.println(txt.charAt(0));  // HSystem.out.println(txt.charAt(4));  // o

Comparing Strings

To compare two strings, you can use theequals() method:

String txt1 = "Hello";String txt2 = "Hello";String txt3 = "Greetings";String txt4 = "Great things";System.out.println(txt1.equals(txt2));  // trueSystem.out.println(txt3.equals(txt4));  // false

Removing Whitespace

Thetrim() method removes whitespace from the beginning and the end of a string:

String txt = "   Hello World   ";System.out.println("Before: [" + txt + "]");System.out.println("After:  [" + txt.trim() + "]");

Complete String Reference

For a complete reference of String methods, go to ourJava String Methods Reference.

The reference contains descriptions and examples of all string methods.

Video: Java Strings