switch statement in c

  • A switch statement allows a variable to be tested for equality against a list of values. Each value is called a case, and the variable being switched on is checked for each switch case.
  • The switch statement is a multi-way branch statement. In the program, if there is a possibility to make a choice from a number of options, then structured selection is useful.
  • It requires only one argument of any data type, which is checked with number of case options.
  • The statement evaluates expression and then looks for its value among the case constants.
  • If the value matches with the case constant, this particular case statement is executed. If not, default is executed.
  • Here switch, case and default are reserved keywords. Every case statement terminates with ‘:’.
  • The break statement is used to exit from current case structure. The switch()statement is useful for writing menu driven program.

    Syntax:

    switch(integer expression)
{
   case constant 1 :
        do this ;
   case constant 2 :
        do this ;
   case constant 3 :
        do this ;
   default :
        do this ;
}

Flow Diagram:

    switch statement in c

    Example:

    #include <stdio.h>
int main()
{
     int num=2;
     switch(num+2)
     {
         case 1:
           printf("Case1: Value is: %d", num);
         case 2:
           printf("Case1: Value is: %d", num);
         case 3:
           printf("Case1: Value is: %d", num);
         default:
           printf("Default: Value is: %d", num);
    }
    return 0;
}

    Output:

    Default: value is: 2