Difference between pre-increment and post-increment in a loop?

Question

Is there a difference in ++i and i++ in a for loop? Is it simply a syntax thing?

Answer 1

There is no difference if you are not using the value after increment in the loop.

for (int i = 0; i < 4; ++i){
cout<

Both the loops will print 0123.

But the difference comes when you uses the value after increment/decrement in your loop as below:

Pre Increment Loop:

for (int i = 0,k=0; i < 4; k=++i){
cout<

Output: 0 0 1 1 2 2 3 3

Post Increment Loop:

for (int i = 0, k=0; i < 4; k=i++){
cout<

Output: 0 0 1 0 2 1 3 2

I hope the difference is clear by comparing the output. Point to note here is the increment/decrement is always performed at the end of the for loop and hence the results can be explained.