Incrementing problem in C++

Question

So, I was learning my C++ course, when I found out that it was teaching var++ for incrementing, but some comment was talking about ++var, and I tried it out and didn't get what I expected, why?
https://sololearn.com/compiler-playground/cZ43V4rlVwLF/?ref=app

Answer 1

Because Var++ is POST INCREMENT OPERATOR and +++Var is PRE increment operator.

For example :
int var=2;
cout<<var++;

It will print 2 because var++ increases itself AFTER YOU WRITE that cout statement.
That's why it's called 'POST' increment operator.

int var=2;
cout<<++var;

This code will give you 3 because '++var' INCREMENTS itself FIRST before executing cout statement. That's why it's called 'PRE' increment operator

Answer 2

Thanks a lot everyone!
Especially Manav Roy , great explanation!

Answer 3

Pourquoi ça te surprend ?
Dans ton code sur SoloLearn :

cpp
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Modifier
int x = 5;
cout << x++; // Affiche 5, x devient 6
cout << ++x; // x devient 7, affiche 7
Tu vois donc 5 puis 7, car x++ utilise d’abord 5, puis l’incrémente, ensuite ++x passe à 7 avant d'afficher.

Bonnes pratiques
Dans une boucle :

cpp
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Modifier
for (int i = 0; i < 10; ++i) { ... }
Utilise ++i si tu n’as pas besoin de l’ancienne valeur. C’est plus clair et parfois plus rapide.