Conditional Statements

These allow you to control the flow of your program based on certain conditions. With conditional statements, you can add logic and decision-making capabilities to your code.

What are Conditional Statements?

Conditional statements are used to decide whether a specific block of code should be executed or not, depending on whether a certain condition is true or false. They form the backbone of many algorithms and programs.

In C++, we mainly use three types of conditional statements:

1. if statement
2. if-else statement
3. switch statement

Let's dive into each one in more detail!

The if Statement

The simplest type of conditional statement is the if statement. It checks if a condition is true, and if so, executes the code inside its block.

#include <iostream>

int main() {
    int age = 17;

    if (age >= 18) {
        std::cout << "You are eligible to vote!";
    }

    return 0;
}

The if-else Statement

The if-else statement adds another branch for when the condition is false.

#include <iostream>

int main() {
    int age = 17;

    if (age >= 18) {
        std::cout << "You are eligible to vote!";
    } else {
        std::cout << "You are not eligible to vote yet.";
    }

    return 0;
}

The switch Statement

The switch statement is used when you need to make a decision based on multiple discrete values of a variable. It's a cleaner alternative to using multiple nested if-else statements.

#include <iostream>

int main() {
    int day = 3;

    switch (day) {
        case 1:
            std::cout << "Monday";
            break;
        case 2:
            std::cout << "Tuesday";
            break;
        case 3:
            std::cout << "Wednesday";
            break;
        default:
            std::cout << "Invalid day number!";
    }

    return 0;
}

Ternary Operator

The ternary operator in C++ is a shorthand way of writing simple if...else statements. It's called "ternary" because it involves three operands.

It takes the following form:

condition ? expression_if_true : expression_if_false

If condition is true, then expression_if_true is evaluated and returned. Otherwise, expression_if_false is evaluated and returned.

#include <iostream>

int main() {
    int a = 10;
    int b = 20;

    int min = (a < b) ? a : b;

    std::cout << min << std::endl;

    return 0;
}

In this example, the a < b condition checks if a is less than b. If so, it evaluates to a (the expression before the colon), and a is assigned to min. If the condition a < b is false (meaning b is less than a), then the expression after the colon (b) is evaluated and assigned to min.

This is an extremely useful operator that can help simplify your code when working with simple conditional expressions.