Loops

Key Concepts

Review core concepts you need to learn to master this subject

while loop in C++.

for loop in C++.

Logical operators in C++.

while loop in C++.

#include <iostream>
using namespace std;

int main() {
  int i;
  i = 1;
  while(i <= 10) { // execute while i is less than or equal to 10
    cout << i << " ";
    i++;
  }
}

In C++, while loop is executed repeatedly while the condition is true. The moment condition becomes false, the loop is exited.

for loop in C++.

#include <iostream>
using namespace std;

int main() {
  int i;
  i = 1;
  while(i <= 10) { // execute while i is less than or equal to 10
    cout << i << " ";
    i++;
  }
}

A for loop in C++ executes a specific number of times. It has three parts: initialization to set the value, condition to test if the loop should continue, and increment/decrement to modify the loop variable.

This example prints 1 to 10 on screen.

Logical operators in C++.

#include <iostream>
using namespace std;

int main() {
  int i;
  i = 1;
  while(i <= 10) { // execute while i is less than or equal to 10
    cout << i << " ";
    i++;
  }
}

In C++, we use logical operators to combine two different conditions. Each condition is evaluated independently and the final result is decided by logical operators.

Following are the logical operators:

&& Logical and operator
|| Logical or operator
! Logical not opertor

&& logical operator requires both conditions to be true. || logical operator requires either of the condition to be true. ! Logical operator negates the result.

Loops

Lesson 1 of 1

1
A loop is a programming tool that repeats some code or a set of instructions until a specified condition is reached. As a programmer, you’ll find that you rely on loops all the time! You’ll h…
2
So first up… the while loop! Before we dive deep into the syntax of the while loop, let’s do a demo. Inside enter_pin.cpp, we have a program that asks and checks for a password. It uses a w…
3
So now that we got a demo of loops, let’s write one! The while loop looks very similar to an if statement. And just like an if statement, it executes the code inside of it if the condition is true…
4
The last one we held your hand, so let’s try one on your own. As an example of iteration, we have the first program ever to run on a stored-program computer (the EDSAC ). It was written and run b…
5
( FoxTrot ) Iterating over a sequence of numbers is so common that C++, like most other programming languages, has a special syntax for it. When we know exactly how many times we want to ite…
6
In the last exercise, we saw an example of an incrementing for loop so here we are going to show you how to write a for loop where the counter goes down. When we know exactly how many times we want…
7
Great job! Key concepts covered in this lesson: - Loops perform repetitive actions so we don’t have to code those actions manually every time. - How to write while loops with a continue conditi…

What you'll create

Portfolio projects that showcase your new skills

Fizz Buzz
Write a program that prints the numbers from 1 to 100. But for multiples of three print "Fizz" instead of the number and for the multiples of five print "Buzz". For numbers which are multiples of both three and five print "FizzBuzz".

How you'll master it

Stress-test your knowledge with quizzes that help commit syntax to memory

Loops
What would be the output of the following code:

while loop in C++.

for loop in C++.

Logical operators in C++.

Fizz Buzz