-= (subtraction assignment)

Availability

Flash Player 4.

Usage

expression1 -= expression2

Parameters

expression1,expression2 A number or expression that evaluates to a number.

Returns

Nothing.

Description

Operator (arithmetic compound assignment); assigns expression1 the value of expression1 - expression2. For example, the following two statements are the same:

x -= y;
x = x - y;

String expressions must be converted to numbers; otherwise, NaN is returned.

Example

Usage 1: The following example uses the -= operator to subtract 10 from 5 and assign the result to the variable x.

x = 5;
y = 10;
x -= y
trace(x);
//returns -5 

Usage 2: The following example shows how strings are converted to numbers.

x = "5";
y = "10";
x -= y;
trace(x);
// returns -5