I have a question about C++

I'm a beginner at C++ and I have a question.

include <iostream>
using namespace std;
void main()
{
    int myage = 25;
    cout << "I am" << myage++ << "years old." << endl;
    cout << "You are" << ++myage << "years old." <<
        endl;
    cout << "She is" << --myage << "years old." << endl;
    cout << "I am" << myage-- << "years old." << endl;
}

If you write the code like this

I am 25 years old.
You are 26 years old.
She is 24 years old.
I am 25 years old.

I think the result should come out like this

I am 25 years old.
You are 27 years old.
She is 26 years old.
I am 26 years old.

If you look at the output, it comes out as above, what's the reason?

c++

2022-09-20 22:18

1 Answers

In C language, ++ or -- is an increase or decrease operator, which increases or decreases the number by 1.

If the increment/decrease operator precedes a variable, it increments or decrements the variable by 1, and if it precedes the variable, it passes the current value first, then increases or decrements by 1.

myage = 25
myage++ // print out the current value of 25 and save 26 plus 1
++myage // output 27 plus 1 from the current value and store 27
--myage // Output 26 minus 1 from the current value of 27 and store 26
myage-- // print out the current value of 26 and save 25 minus 1

Therefore, it is correct to follow the results below.

2022-09-20 22:18

If you have any answers or tips

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