Flow Control and Exception Handling - while Statement

Syntax (JLS §14.11)

    while( boolean expression ) {
        statement(s);
    }

• executes statement(s) repeatedly until the value of expression is false
• if the expression is false the first time, the statements will never execute

    int i = 1;
    
    while( i>3 ) {
        System.out.println("This shouldn't print");
    }

• both the break and continue statements can be used to alter the processing of a while loop

    while( i < 10 ){
        if( i == 5 ) break;     // break out of loop
        System.out.println(i);
        i++;
    }

    while( i < 10 ){
        if( i==5 ) { 
           i++;
           continue;   // force next loop
        }
        
        System.out.println(i);
        i++;
    }

Example Code

• TestWhile.java

Traps

• non-boolean expression
• using '=' instead of '==' for boolean expression