C++ if Statement

In this lesson, we will learn how to use the if..statement in C++ to write a decision-making program, with examples. In C++, there are three types of if…else statements. We will learn about the three different types in the next lessons.

C++ if Statements

The if statement is used in computer programming to run one piece of code under specific criteria and a different block of code under different ones.

Basic Syntax

if(condition){
// statements
}

In the above syntax, the condition is a Boolean expression that returns True or False;

Flowchart of if statement in C++

Example of if condition in C++

// Program checks if a number is even
#include <iostream>

using namespace std;
int main() {
  int checkNumber;
  cout << "Please enter a number: ";
  cin >> checkNumber;
  if (checkNumber % 2 == 0)
    cout << checkNumber << " is an even number.";
  return 0;
}

Output

Please enter a number: 4
4 is an even number.

The above program uses an if statement to decide whether or not 4 % 2 == 0 is true. The checkNumber is even if this condition is true. If not, nothing will be displayed. So, the program will display “4 is an even number”.

This concludes the C++ if Statement lesson. The next lesson will teach you the if..else Statement in C++.