Slide 7.9: The break statement

The break Statement

Java supports three jump statement: break, continue, and return. These three statements transfer control to other part of the program. The break statement can be used to “jump out” of a loop statement.

This example jumps out of the loop when i is equal to 4. In Java, break is majorly used for:

1for ( int i = 0; i < 10; i++ ) {
2  if ( i == 4 )  break;
3  System.out.print( i );
4}    // Output: 0123

Terminating a sequence in a switch statement (discussed previously)

Using break to exit a loop: Using break, we can force immediate termination of a loop, bypassing the conditional expression and any remaining code in the body of the loop.

Using break as a form of goto: Java does not have a goto statement. Instead, Java uses label, which is used to identify a block of code. Break statement can be use to jump out of target block, but you cannot break to any label which is not defined in an enclosing block.

1label: {
2  statement1;
3  statement2;
4  statement3;
5     .
6     .
7}

BreakLabel.java (the break statement)

01// Using break with goto
02class BreakLabel { 
03  public static void main( String args[ ] ) { 
04    boolean t = Boolean.parseBoolean( args[0] ); 
05    first: { 
06      second: { 
07        third: { 
08          // Before break 
09          System.out.println( "Before the break" ); 
10          // break will take the control out of second block. 
11          if ( t )  break second; 
12          System.out.println( "Won't execute if true." ); 
13        }  // End of third block
14        System.out.print( "Won't execute if true." ); 
15      }  // End of second block
16      System.out.println( "After second block" ); 
17    }  // End of first block
18  } 
19}

shell> java BreakLabel