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Syntax:

	switch (expression)
	{
	 case value1:
			statements
	 case value2:
			statements
	   ...
	 default: statements  
	}

If the expression evaluates to value1, execution inside the braces starts after the label value1:. Similarly for any other values that are given as cases. If none of the case values matches, the default section is executed.

The default section is optional. If it is not there, execution just continues after the ending brace of the switch.

Example:

	switch (keyCode)
	{
	case insKey: insert ();
			break;
	case backKey:
	case delKey: delete ();
			break;
	default: append (keyCode);
	}

It is usual to put break; at the end of each section to make execution jump out there and continue after the ending brace of the switch. If the break; is not there, execution continues into the next case section; sometimes that is desired, as in the backKey case in the example above.

Constraints on the switch statement

The expression in switch (expression) must evaluate to byte, short, int or char. Not boolean, float, double or long.
The compiler must be able to fully evaluate the value in case value:. No run-time expressions.
You cannot have two or more case values the same.
The case values must lie within the valid range of the data type of the switch expression.

Java training course

Conditional statements (2) - switch

Syntax:

Example:

Constraints on the switch statement