Switch Statement

Overview

Switch statements are used when comparing a single variable against a series of constants. They are often cleaner and slightly faster than long if-else if chains.

Syntax

cpp

char grade = 'B';

switch (grade) {
    case 'A':
        cout << "Excellent";
        break; // Crucial to prevent fall-through
    case 'B':
        cout << "Good";
        break;
    default:
        cout << "Unknown grade";
}

Common Pitfalls

Forgetting the `break;` statement, causing multiple unrelated cases to execute consecutively.
Trying to use floating-point numbers or strings as switch expressions.

Interview Tips

Switch statements in C++ can only evaluate integral or enum types (e.g., int, char, enum). You cannot use std::string in a switch statement.
Understand 'fall-through' behavior where omitting a 'break' causes the next case to execute.

Real-World Example

A simple menu selection system.

example

cpp

#include <iostream>
using namespace std;

int main() {
    int choice = 2;
    
    switch (choice) {
        case 1: cout << "Starting game...\n"; break;
        case 2: cout << "Loading settings...\n"; break;
        case 3: cout << "Exiting...\n"; break;
        default: cout << "Invalid selection.\n";
    }
    return 0;
}

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