Java Programming/Keywords/switch

switch is a Java keyword.

It is a branching operation, based on a number. The 'number' must be either char , byte , short , or int primitive type.

Syntax:

switch  ( <integer-var> )
{
 case  <label₁>: <statements>;
 case  <label₂>: <statements>;
 ...
 case  <label_n>: <statements>;
 default : <statements>;
}

When the <integer-var> value match one of the <label>, then: The statements after the matched label will be executed including the following label's statements, until the end of the switch block, or until a break keyword is reached.

For example:

Computer code

intvar= 3;
switch(var)
{
case1:
System.out.println("Case: 1");
System.out.println("Execute until break");
break;
case2:
System.out.println("Case: 2");
System.out.println("Execute until break");
break;
case3:
System.out.println("Case: 3");
System.out.println("Execute until break");
break;
case4:
System.out.println("Case: 4");
System.out.println("Execute until break");
break;
default:
System.out.println("Case: default");
System.out.println("Execute until break");
break;
}

The output from the above code is:

Case: 3
Execute until break

The same code can be written with if-else blocks":

Computer code

intvar= 3;
if(var== 1 ) {
System.out.println("Case: 1");
System.out.println("Execute until break");
}elseif(var== 2 ) {
System.out.println("Case: 2");
System.out.println("Execute until break");
}elseif(var== 3 ) {
System.out.println("Case: 3");
System.out.println("Execute until break");
}elseif(var== 4 ) {
System.out.println("Case: 4");
System.out.println("Execute until break");
}else{
// -- This is the default part -- 
System.out.println("Case: default");
System.out.println("Execute until break");
}