The usage of pre-increment and post-increment operators

This code snippet demonstrates the usage of pre-increment and post-increment operators in C++.

Code

/**
* Main function that demonstrates the usage of pre-increment and post-increment operators.
 *
 * @return 0 indicating successful execution
 *
 * @throws None
 */

#include <iostream>
using namespace std;

int main() {
    int numberOne = 1;
    int numberTwo = 2;
    int numberThree = 3;
    int numberFour = 4;

    // numberOne current value is 1
    int result = numberOne++; // Assignment and increment after the operation
    cout << "Number One: " << numberOne << endl;
    cout << "Result: " << result << endl;
    cout << "----" << endl;

    //numberTwo current value is 2
    result = ++numberTwo; // Increment and assignment before the operation
    cout << "Number Two: " << numberTwo << endl;
    cout << "Result: " << result << endl;
    cout << "----" << endl;

    //numberThree current value is 3
    result = numberThree--; // Assignment and decrement after the operation
    cout << "Number Three: " << numberThree << endl;
    cout << "Result: " << result << endl;
    cout << "----" << endl;

    //numberFour current value is 4
    result = --numberFour; // Decrement and assignment before the operation
    cout << "Number Four: " << numberFour << endl;
    cout << "Result: " << result << endl;

    return 0;
}

Explanation

The provided C++ code is a simple demonstration of the usage of pre-increment (++var), post-increment (var++), pre-decrement (–var), and post-decrement (var–) operators in C++.

The main function starts by declaring four integer variables numberOne, numberTwo, numberThree, and numberFour with initial values of 1, 2, 3, and 4 respectively.

The first operation is numberOne++. This is a post-increment operation, which means the current value of numberOne is assigned to result before numberOne is incremented. Therefore, result will be 1 (the original value of numberOne), and numberOne will be incremented to 2.

Next, the operation ++numberTwo is a pre-increment operation. Here, numberTwo is incremented before the assignment operation. So, numberTwo becomes 3, and this new value is assigned to result.

The third operation is numberThree–, a post-decrement operation. Similar to the post-increment, the current value of numberThree is assigned to result before numberThree is decremented. So, result will be 3, and numberThree will be decremented to 2.

Finally, the operation –numberFour is a pre-decrement operation. Here, numberFour is decremented before the assignment operation. So, numberFour becomes 3, and this new value is assigned to result.

After each operation, the new values of the variables and result are printed to the console for verification. The function then returns 0, indicating successful execution.

Output

Number One: 2
Result: 1
----
Number Two: 3
Result: 3
----
Number Three: 2
Result: 3
----
Number Four: 3
Result: 3

Process finished with exit code 0