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The Simple if Statement

The Simple if Statement

Learn how C++ uses the simple if conditional statement.

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In programming, we often come across points where we have to make a decision based on certain input or output of a statement. In C++, to do this, we use some statements called conditional statements. We’ll start with the most basic conditional statement, the if statement.

if() statement

The if statement takes one argument of type bool or an expression that returns a bool value. Upon execution of the if statement, the compiler moves to the if enclosed bracket if and only if the condition inside the if statement is true. Here, take a look at the flow diagram of the working conditional statement.

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if statement execution
if statement execution

The syntax to write an if statement is:

if (<condition>)
{
    //if-enclosed code
}
Syntax of if statement in C++

The if statement, as you can see, is followed by a bracket () containing the condition, and doesn’t end with a semicolon. After that, the code that is to be executed if the condition within the brackets is true is added. This if code block is enclosed between opening and closing curly braces. Note that if there is only one line of code in the if code block, we can do away with the curly braces. However, best practice in writing such code is to always add code, be it one line or multiple lines, within the curly braces.

Let’s look at an example that uses a simple if statement:

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C++
#include <iostream>
using namespace std;
int main() {
    int age = 25;
    if (age >= 18) {
        cout << "You are an adult." << endl;
    }
    return 0;
}

This code demonstrates a basic if statement. On line 7, the program checks if the age variable is greater than or equal to 18. If the condition is true, ...