C++ Switch-case Statement

In C++, the switch-case statement provides a convenient way to execute different blocks of code based on the value of a variable or an expression. It allows you to compare a single value against multiple cases and perform different actions accordingly. In this article, we will explore the usage of the switch-case statement in C++ with examples.

1. Basic switch-case Statement

The most basic form of a switch-case statement consists of the switch keyword followed by a variable or an expression enclosed in parentheses. Each case represents a specific value or a range of values that will be compared against the switch variable. Here's an example:

#include <iostream>
int main() {
int day = 3;


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switch (day) {
    case 1:
        std::cout << "Monday" << std::endl;
        break;
    case 2:
        std::cout << "Tuesday" << std::endl;
        break;
    case 3:
        std::cout << "Wednesday" << std::endl;
        break;
    case 4:
        std::cout << "Thursday" << std::endl;
        break;
    case 5:
        std::cout << "Friday" << std::endl;
        break;
    default:
        std::cout << "Invalid day" << std::endl;
        break;
}

return 0;
}

In the above code, we use a switch-case statement to check the value of the variable day. Depending on its value, the corresponding case is executed. If none of the cases match, the default case is executed.

2. Multiple Cases

In C++, you can group multiple cases together to execute the same block of code for different values. Here's an example:

#include <iostream>
int main() {
char grade = 'B';

c
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switch (grade) {
    case 'A':
    case 'a':
        std::cout << "Excellent" << std::endl;
        break;
    case 'B':
    case 'b':
        std::cout << "Good" << std::endl;
        break;
    case 'C':
    case 'c':
        std::cout << "Average" << std::endl;
        break;
    default:
        std::cout << "Invalid grade" << std::endl;
        break;
}

return 0;
}

In the above code, we use the switch-case statement to check the value of the variable grade. We group the cases for both uppercase and lowercase grades together to execute the same block of code.

3. Fallthrough

By default, after executing a case, the control will exit the switch block. However, sometimes you may want to execute multiple cases consecutively. In such cases, you can use the fallthrough behavior by omitting the break statement. Here's an example:

#include <iostream>
int main() {
int num = 3;

c
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switch (num) {
    case 1:
        std::cout << "One" << std::endl;
        // Fallthrough
    case 2:
        std::cout << "Two" << std::endl;
        // Fallthrough
    case 3:
        std::cout << "Three" << std::endl;
        break;
    default:
        std::cout << "Invalid number" << std::endl;
        break;
}

return 0;
}

In the above code, when the variable num is 3, the cases for both 2 and 3 will be executed. This behavior is achieved by omitting the break statement after the case for 2.

The switch-case statement provides a flexible way to handle multiple conditions based on the value of a variable or an expression. It is particularly useful when you have a fixed set of possible values to compare against. Practice using switch-case statements with different scenarios, including fallthrough behavior and multiple cases, to effectively control the flow of your C++ programs.