MACROMEDIA FLEX-FLEX ACTIONSCRIPT LANGUAGE Reference page 114

This statement adds the floating-point numbers 2.5 and 3.25 and writes the resulting floating-
point number, 5.75, to the log file:
trace(2.5+3.25);
The following example shows how numeric sums to the right of a string expression are not
calculated:
var a:String = 3 + 10 + "asdf";
trace(a); // 13asdf
var b:String = "asdf" + 3 + 10;
trace(b); // asdf310
+= (addition assignment)
Availability
Flash Player 4.
Usage
expression1 += expression2
Parameters
expression1,expression2
Returns
A string or a number.
Description
Operator (arithmetic compound assignment); assigns
. For example, the following two statements have the same result:
expression2
x += y;
x = x + y;
This operator also performs string concatenation. All the rules of the addition (+) operator apply
to the addition assignment
For more information, see
Example
Usage 1: This example uses the
Gilbert" to the log file.
var x1:String = "My name is ";
x1 += "Gilbert";
trace(x1); // output: My name is Gilbert
Usage 2: The following example shows a numeric use of the addition assignment (
var x:Number = 5;
var y:Number = 10;
x += y;
trace(x); // output: 15
114 Chapter 5: ActionScript Core Language Elements
// output: 5.75
A number or string.
operator.
(+=)
"Operator precedence and associativity" on page
operator with a string expression and writes "My name is
+=
the value of
expression1 expression1 +
32.
operator:
+=)