Guess the Output of C++ Program Part 1

Welcome to our output guessing article, we will present you with a simple C++ program, and we invite you to take a guess a what the output will be. Once you have made your guess, we will dive into the code, breaking it down step by step to unravel the mystery and explain the final output

The Code:

#include <iostream>
using namespace std;

int main(){
    int x = 10;

    while (x --> 0){
        cout << x << " ";
    }
    cout << endl;
}

Your Turn: Guess the Output!

Before we reveal the output, take a moment to think about what the program will print to the console. What sequence of numbers do you expect to see?

Breaking Down the Code:

Let's dissect the code to understand its logic and behavior.

1. Initialization:

int x = 10;

The variable x is initialized with the value 10.

2. While Loop:

while (x --> 0){
    cout << x << " ";
}

The loop condition uses the post-decrement operator (--). This operator is equivalent to x-- > 0, meaning “decrement x after evaluating the condition.”

3. Output:

This line adds a newline character to the output.

Understanding the Output:

The loop iterates while the condition x-- > 0 is true. Let's break down the iterations:

1. Iteration 1: x = 10, condition (10 > 0) is true, output: 9.
2. Iteration 2: x = 9, condition (9 > 0) is true, output: 8.
3. Iteration 3: x = 8, condition (8 > 0) is true, output: 7.
   .
   .
   .
4. Iteration 8: x = 2, condition (2 > 0) is true, output: 1.
5. Iteration 9: x = 1, condition (1 > 0) is true, output: 0.
6. Iteration 8: x = 0, condition (0 > 0) is false, exit the loop.

The post-decrement operator (--) in C++ is a unary operator that decreases the values of the variable by 1 after its current value is used in the expression where it appears.

The Revealed Output:

The output of the code will be:

9 8 7 6 5 4 3 2 1 0