Understanding the Switch Statement in C with Simple Examples

Simple Switch Statement in C

Introduction
In C programming, the switch statement allows you to make decisions based on different values of a single variable. It’s an alternative to using multiple if-else statements, making the code cleaner and easier to read. In this post, we’ll break down the switch statement and go through a simple example to help you understand how it works.

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What is a Switch Statement?

A switch statement in C evaluates the value of a variable or expression and executes a block of code based on that value. It’s particularly useful when you need to compare a single variable to multiple potential values.

The basic structure looks like this:

switch (variable) {
    case value1:
        // Code to execute if variable == value1
        break;
    case value2:
        // Code to execute if variable == value2
        break;
    default:
        // Code to execute if variable doesn't match any case
}

Key Points to Remember:

1. Each case represents a possible value of the variable.
2. The break statement prevents the code from running into the next case.
3. The default case is optional and runs when none of the cases match.

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Example Program: Basic Calculator with Switch

Let’s create a simple calculator that can perform addition, subtraction, multiplication, or division based on the user’s choice.

#include <stdio.h>

int main() {
    int num1, num2;
    char operator;

    // Ask the user for input
    printf("Enter an operator (+, -, *, /): ");
    scanf(" %c", &operator);

    printf("Enter two numbers: ");
    scanf("%d %d", &num1, &num2);

    switch (operator) {
        case '+':
            printf("%d + %d = %d\n", num1, num2, num1 + num2);
            break;
        case '-':
            printf("%d - %d = %d\n", num1, num2, num1 - num2);
            break;
        case '*':
            printf("%d * %d = %d\n", num1, num2, num1 * num2);
            break;
        case '/':
            if (num2 != 0)
                printf("%d / %d = %d\n", num1, num2, num1 / num2);
            else
                printf("Division by zero is not allowed.\n");
            break;
        default:
            printf("Invalid operator\n");
    }

    return 0;
}

How the Code Works

1. The program asks the user to input an operator (+, -, *, or /).
2. Then, it requests two numbers for the calculation.
3. Using the switch statement, it checks the operator:

• If the operator is +, it adds the numbers.
• If the operator is -, it subtracts the numbers.
• If the operator is *, it multiplies the numbers.
• If the operator is /, it divides the numbers (after checking for division by zero).

1. If the user enters an invalid operator, the default case runs, and an error message is displayed.

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Conclusion
The switch statement is a powerful tool in C programming. It makes your code easier to read and manage, especially when you have multiple conditions based on a single variable. Practice by modifying this example—try adding more cases or creating a different program!

Happy Coding!