Switch

The control statement that allows us to make a decision from the number of choices is called a switch statement.

Syntax:

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


Examples:
1.//program

#include<stdio.h>
#include<conio.h>
int main()
{
int i=2;
switch(i)
{
case 1:
printf("in class 1");
break;
case 2:
printf("in class 2");
break;
case 3:
printf("in class 3");
break;
default:
printf("in default");

}
getch();
return 0;

}

output:
in class 2


2.//without break

#include<stdio.h>
#include<conio.h>
int main()
{
int i=2;
switch(i)
{
case 1:
printf("in class 1\n");

case 2:
printf("in class 2\n");

case 3:
printf("in class 3\n");

default:
printf("in default\n");

}
getch();

return 0;

}

output:

in class 2

in class 3

in default

//It executes the 2 case and all the remaining cases after the 2 case as the break statement is not present.

//We can write the cases in any order, not necessarily in ascending or descending order.

3.//cases arranged in random order

#include<stdio.h>
#include<conio.h>
int main()
{
int i=2;
switch(i)
{
case 1:
printf("in class 1\n");

case 3:
printf("in class 3\n");

   case 2:
printf("in class 2\n");

default:
printf("in default\n");

}
getch();
return 0;

}

output:

in class 2

in default

4.//Arithmetic operations -break statement is not present

#include<stdio.h>

#include<conio.h>

int main()

{

int a,b,x;

printf("enter two values\n");

scanf("%d%d",&a,&b);

printf("select operation +=1 or -=2 or /=3 or *=4 or %=5\n");

scanf("%d",&x);

switch(x)

{

case 1:

printf("sum of two numbers is %d\n",a+b);

case 2:

printf("difference of two numbers is %d\n",a-b);

case 4:

printf("product of two numbers is %d\n",a*b);

case 3:

printf("division of two numbers is %d\n",a/b);

case 5:

printf("modular division results %d\n",a%b);

default:

printf("enter any one of the operations");

}

getch();

return 0;

}

output:

enter two values

10

2

+=1 or -=2 or /=3 or *=4 or %=5

1

sum of two numbers is 12

difference of two numbers is 8

product of two numbers is 20

division of two numbers is  5

modular division results 0

enter any one of the operations

5.//To print month

#include<stdio.h>

#include<conio.h>

int main()

{

int month;

printf("enter month\n");

scanf("%d",&month);

switch(month)

{

case 1:

printf("january");

break;

case 2:

printf("February");

break;

case 3:

printf("March");

break;

case 4:

printf("April");

break;

case 5:

printf("May");

break;

case 6:

printf("June");

break;

case 7:

printf("July");

break;

case 8:

printf("August");

break;

case 9:

printf("September");

break;

case 10:

printf("October");

break;

case 11:

printf("November");

break;

case 12:

printf("December");

break;

}

getch();

return 0;

}

output:

enter month

5

May