C Decision & Loops

if….else Statement

Decision making are needed when, the program encounters the situation to choose a particular statement among many statements. C programming provides following statements to make decision makings:

·         if…else statement

·         switch statement

if(test expression)

     statements to be executed if test expression is true;

Nested if…else statement (if…else Statement)

The if…else statement can be used in nested form when a serious decision are involved. The ANSI standard specifies that 15 levels of nesting may be continued.

Syntax of nested if…else Statement:

if(test expression)

     statement to be executed if test expression is true;

else

     if(test expression 1)

          statements to be executed if test expression 1 is true;

     else if

     .

     .

     .

       else

          statements to be executed if all test expressions are false;

How nested if…else works?

If the test expression is true, it will execute the relevant code but, if it is false, the control of the program jumps to the else part and check test expression 1 and the process continues. If all the test expressions are false then, only the last statement is executed.