Loops

Loops

• Loop is to repeat the action over and over again
• This condition to terminate or exit a loop is referred as loop control expression
• C provide two looping statements namely: for, while and do...while
  

The while loop

• pretest loop
• It used an expression to control the loop
• It test the expression before every iteration of the loop
  

       while (expression){
             Statements
       }

• As long as the expression is evaluated to true the statements in the loop body will be repeated.

The for loop

• a pretest loop
• uses three expression
• first expression contains initialization statements
• the second contains the limit-test expression
• the third contains the updating expression
• A for loop is normally used when the number of times of the loop to be executed are knowns
  

       for(initialization; limit-test; updating){
             Statements;
       }

• As long as the limit-test is evaluated to true the statements in the loop body will be repeated.

The do...while loop

• a post-test loop
• It also uses an expression to control the loop
• It tests the expression after the execution of the body
• The do…while loop end with a semicolon
• The do…while loop only test the expression at the end of the loop, the body of the loop will be at least execute for once
  

       do{
              Statements;
       }while (expression);

• As long as the expression is evaluated to true the statements in the loop body will be repeated.