Why do people write --i? [duplicate]

Question

Possible Duplicate:
Incrementing in C++ - When to use x++ or ++x?

I've seen things like i++ commonly used in, say, for loops. But when people use -- instead of ++, for some reason some tend to write --i as opposed to i--.

Last time I checked, they both work (at least in JavaScript). Can someone tell me if this is so in other C-family languages, and if it is, why do some people prefer --i to i--?

Answer 1

++i is faster than i++. Why? See the simple explication.

i++

i++ will increment the value of i, but return the pre-incremented value.

• temp = i
• i is incremented
• temp is returned

Example:

i = 1;
j = i++;
(i is 2, j is 1)

++i

++i will increment the value of i, and then return the incremented value.

Example:

i = 1;
j = ++i;
(i is 2, j is 2)

This is simillar for --i and i--.