switch statement in C

In this post you will learn about switch case statement in C programming language.The control statement that allows us to make a decision from the number of choices is called a  switch statement.Switch statement is a control statement that allows us to choose only one choice among the many given choices. The expression in switch evaluates to return an integral value, which is then compared to the values present in different cases. It executes that block of code which matches the case value. If there is no match, then default block is executed(if present).
The general form of switch statement is:

switch(integer expression)
{
    case value-1:
        block-1;
        break;
    case value-2:
        block-2;
        break;
    case value-3:
        block-3;
        break;
    case value-4:
        block-4;
           break;
    default:
           default-block;
        break;
}

Example:

#include<stdio.h>
void main( )
{
    int a, b, c, choice;
    while(choice != 3)
    {
        /* Printing the available options */
        printf("\n 1. Press 1 for addition");
        printf("\n 2. Press 2 for subtraction");
        printf("\n Enter your choice");
        /* Taking users input */
        scanf("%d", &choice);
      
        switch(choice)
        {
            case 1:
                printf("Enter 2 numbers");
                scanf("%d%d", &a, &b);
                c = a + b;
                printf("%d", c);
                break;
            case 2:
                printf("Enter 2 numbers");
                scanf("%d%d", &a, &b);
                c = a - b;
                printf("%d", c);
                break;
            default:
                printf("you have passed a wrong key");
                printf("\n press any key to continue");
        }
    }
}

Example 2:

int main()
{
int i;
printf("enter an integer");
scanf("%d",&i);
switch(i)
{
case 1: printf("one");
            break;
case 2: printf("two");
            break;
case 3: printf("three");
            break;
case 4: printf("four");
             break;
default: printf("invalid number");
}
return 0;
}
There are some things that you simply cannot do with a  switch .
These are:
(a)  A float expression cannot be tested using a  switch 
(b)  Cases can never have variable expressions (for example it is
wrong to say  case a +3 :  )
(c)  Multiple cases cannot use same expressions.