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6 - Declarations
6.1 Number Per Line
One declaration per line is recommended since it encourages commenting. In other words,
int level; // indentation levelint size; // size of tableint level, size;
Do not put different types on the same line. Example:
int foo, fooarray[]; //WRONG!
Note: The examples above use one space between the type and the identifier. Another acceptable alternative is to use tabs, e.g.:
int level; // indentation levelint size; // size of tableObject currentEntry; // currently selected table entry6.2 Initialization
Try to initialize local variables where they're declared. The only reason not to initialize a variable where it's declared is if the initial value depends on some computation occurring first.
6.3 Placement
Put declarations only at the beginning of blocks. (A block is any code surrounded by curly braces "{" and "}".) Don't wait to declare variables until their first use; it can confuse the unwary programmer and hamper code portability within the scope.
void myMethod() { int int1 = 0; // beginning of method block if (condition) { int int2 = 0; // beginning of "if" block ... }}</blockquote> The one exception to the rule is indexes offor loops, which in Java can be declared in thefor statement:
for (int i = 0; i < maxLoops; i++) { ... }</blockquote>Avoid local declarations that hide declarations at higher levels. For example, do not declare the same variable name in an inner block:
int count;...myMethod() { if (condition) { int count = 0; // AVOID! ... } ...}6.4 Class and Interface Declarations
When coding Java classes and interfaces, the following formatting rules should be followed:
- No space between a method name and the parenthesis "(" starting its parameter list
- Open brace "{" appears at the end of the same line as the declaration statement
- Closing brace "}" starts a line by itself indented to match its corresponding opening statement, except when it is a null statement the "}" should appear immediately after the "{"
class Sample extends Object { int ivar1; int ivar2; Sample(int i, int j) { ivar1 = i; ivar2 = j; } int emptyMethod() {} ...}