CONTENTS | PREV | NEXT | Java Code Conventions |
One declaration per line is recommended since it encourages commenting. In other words,
int level; // indentation level
int size; // size of table
is preferred over
int level, size;
In absolutely no case should variables and functions be declared on the same line. Example:
long dbaddr, getDbaddr(); // WRONG!
Do not put different types on the same line. Example:
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 level
int size; // size of table
Object currentEntry; // currently selected table entry
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; // beginning of method block
if (condition) {
int int2; // beginning of "if" block
...
}
}
The one exception to the rule is indexes of for loops, which in Java can be declared in the for statement:
for (int i = 0; i < maxLoops; i++) { ...
Avoid local declarations that hide declarations at higher levels. For example, do not declare the same variable name in an inner block:
int count;
...
func() {
if (condition) {
int count; // AVOID!
...
}
...
}
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.
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() {}
...
}