Simple Calculator Program using Switch Case: C

In this video tutorial we shall perform Addition, Subtraction, Multiplication and Division of numbers based on user input, using switch case statement(decision control statement).

Related Read:
Basic Arithmetic Operations In C
Addition of 2 Numbers: C
Subtraction of 2 Numbers: C
Multiplication of 2 Numbers: C
Division of 2 Numbers: C
else if statement in C

We had written same calculator program using else-if clause. Same program has been modified to use Switch case in this program.
Simple Calculator Application In C

Simple Calculator using Switch Case: C Program

Working of Calculator Program
We display list of operation one can perform. That is,

1. Addition
2. Subtraction
3. Multiplication
4. Division

We ask the user to input his / her choice for arithmetic operation. If the user selects 1, then we ask the user to enter 2 integer numbers to perform addition operation. Once the user enters 2 integer numbers we add and display the result on the screen.

If the user enters wrong choice, we ask the user to enter proper choice.

Calculator Program using Switch Case: C Program

#include < stdio.h >

int main()
{
    int a, b;
    char choice;

    printf("Enter your choice\n");
    printf("a. Addition\nb. Subtraction\nc. Multiplication\nd. Division\n");
    scanf("%c", &choice);


   printf("Enter 2 integer numbers\n");
   scanf("%d %d", &a, &b);


    switch(choice)
    {
        case 'a': printf("%d + %d = %d\n", a, b, (a+b));
                break;

        case 'b': printf("%d - %d = %d\n", a, b, (a-b));
                break;

        case 'c': printf("%d x %d = %d\n", a, b, (a*b));
                break;

        case 'd': if( b != 0)
                    printf("%d / %d = %d\n", a, b, (a/b));
                else
                    printf("Number can't be divided by 0\n");
                break;

        default: printf("You entered wrong choice\n");
                 break;
    }

    return 0;
}

Output
Enter your choice
a. Addition
b. Subtraction
c. Multiplication
d. Division
c
Enter 2 integer numbers
5
10
5 x 10 = 50

In above program we are asking user to enter character a or b or c or d to perform addition, subtraction, multiplication and division operations respectively.

#include < stdio.h >

int main()
{
    int a, b, choice;

    printf("Enter your choice\n");
    printf("1. Addition\n2. Subtraction\n3. Multiplication\n4. Division\n");
    scanf("%d", &choice);

    if( choice > 4 )
    {
        printf("Select with in the range!\n");
    }
    else
    {
        printf("Enter 2 integer numbers\n");
        scanf("%d %d", &a, &b);
    }


    switch(choice)
    {
        case 1: printf("%d + %d = %d\n", a, b, (a+b));
                break;

        case 2: printf("%d - %d = %d\n", a, b, (a-b));
                break;

        case 3: printf("%d x %d = %d\n", a, b, (a*b));
                break;

        case 4: if( b != 0)
                    printf("%d / %d = %d\n", a, b, (a/b));
                else
                    printf("Number can't be divided by 0\n");
                break;

        default: printf("You entered wrong choice\n");
                 break;
    }

    return 0;
}

Output:
Enter your choice
1. Addition
2. Subtraction
3. Multiplication
4. Division
4
Enter 2 integer numbers
10
2
10 / 2 = 5

Here we are asking user to enter 1 or 2 or 3 or 4 to choose the arithmetic operation.

#include

int main()
{
    int a, b;
    char choice;

    printf("Enter your choice\n");
    printf("1. Addition\n2. Subtraction\n3. Multiplication\n4. Division\n");
    scanf("%c", &choice);

    printf("Enter 2 integer numbers. Format: a + b\n");
    scanf("%d %c %d", &a, &choice, &b);



    switch(choice)
    {
        case '+': printf("%d + %d = %d\n", a, b, (a+b));
                break;

        case '-': printf("%d - %d = %d\n", a, b, (a-b));
                break;

        case '*': printf("%d x %d = %d\n", a, b, (a*b));
                break;

        case '/': if( b != 0)
                    printf("%d / %d = %d\n", a, b, (a/b));
                else
                    printf("Number can't be divided by 0\n");
                break;

        default: printf("You entered wrong choice\n");
                 break;
    }

    return 0;
}

Output:
Enter your choice
1. Addition
2. Subtraction
3. Multiplication
4. Division
1
Enter 2 integer numbers. Format: a + b
50 + 60
50 + 60 = 110

Here we ask the user to enter values as well as the operation to be performed. Operands and operator.

Note 1: There is no need of curly braces inside case.
Note 2: If a case doesn’t end with break statement, then the execution continues and the block of code present inside next case will also get executed.
Note 3: default case is optional. And the code inside it executes only when non of the cases match.
Note 4: Here switch, case, break, default are all keywords / reserve words.

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