# ++ (increment)

#### Availability

Flash Player 4.

#### Usage

    ++expression
    expression++

#### Parameters

None.

#### Returns

Nothing.

#### Description

Operator (arithmetic); a pre-increment and post-increment unary operator that adds 1 to `expression`. The `expression` can be a variable, element in an array, or property of an object. The pre-increment form of the operator (`++expression`) adds 1 to `expression` and returns the result. The post-increment form of the operator (`expression++`) adds 1 to `expression` and returns the initial value of `expression` (the value prior to the addition).

The pre-increment form of the operator increments `x` to 2 (`x + 1 = 2`), and returns the result as `y`:

    x = 1;
    y = ++x
    //y is equal to 2

The post-increment form of the operator increments `x` to 2 (`x + 1 = 2`), and returns the original value of `x` as the result `y`:

    x = 1;
    y = x++;
    //y is equal to 1

#### Example

The following example uses ++ as a post-increment operator to make a `while` loop run five times.

    i = 0;
    while(i++ < 5){
    trace("this is execution " + i);
    }

This example uses ++ as a pre-increment operator.

    var a = [];
    var i = 0;
    while (i < 10) {
    	a.push(++i);
    }
    trace(a.join());

This script displays the following result in the Output window:

    1,2,3,4,5,6,7,8,9,10

The following example uses ++ as a post-increment operator.

    var a = [];
    var i = 0;
    while (i < 10) {
    a.push(i++);
    	}
    trace(a.join());

This script displays the following result in the Output window:

    0,1,2,3,4,5,6,7,8,9