javascript i++ vs ++i [duplicate]

The difference between i++ and ++i is the value of the expression.

The value i++ is the value of i before the increment. The value of ++i is the value of i after the increment.

Example:

var i = 42;
alert(i++); // shows 42
alert(i); // shows 43
i = 42;
alert(++i); // shows 43
alert(i); // shows 43

The i-- and --i operators works the same way.