C: What is the difference between ++i and i++?

Question

In C, what is the difference between using ++i and i++, and which should be used in the incrementation block of a for loop?

Answer 1

The difference can be understood by this simple C++ code below:

int i, j, k, l;
i = 1; //initialize int i with 1
j = i+1; //add 1 with i and set that as the value of j. i is still 1
k = i++; //k gets the current value of i, after that i is incremented. So here i is 2, but k is 1
l = ++i; // i is incremented first and then returned. So the value of i is 3 and so does l.
cout << i << ' ' << j << ' ' << k << ' '<< l << endl;
return 0;