Switch Statement

A switch statement allows a variable or value of an expression to be tested for equality against a list of possible case values and when match is found, the block of code associated with that case is executed.

Syntax of Switch Statement

switch(expression) {

case constant1 : /* code block1 */

statement1; break;

case constant2 : /* code block 2 */ statement; break; case constant3 : /* code block 3 */ statement; break;

default : /* Optional */ statement; }

Flow chart

Rules for using switch:

1. The expression (after switch keyword) must yield an integer value i.e it can be an integer or a variable or an expression that evaluates to an integer.

2. The case label i.e values must be unique.

3. The case label must end with a colon(:)

4. The following line, after case statement, can be any valid C statement.

Example

#include <stdio.h>

 int main ()

 { char grade = 'B';

 switch(grade)

{ case 'A' : printf("Excellent!\n" );

break;

case 'B' : printf("Well done\n" );

break;

 case 'C' : printf("Good\n" );

 break;

case 'D' : printf("You passed\n" );

 break;

case 'F' : printf("Better try again\n" );

break;

default : printf("Invalid grade\n" );

}

 printf("Your grade is %c\n", grade );

return 0; }

The output of the above program is : Well done Your grade is B