Function Literals
ActionScript allows us to create function literals, which are convenient when we need a function temporarily or when we’d like to use a function where an expression is expected.
Function literals have the same syntax as standard function declarations except that the function name is omitted and there’s a semicolon after the statement block. The general form is:
function (param1
,param2
, ...paramn
) {statements
};
where param1,param2,...paramn
is an
optional list of parameters and statements
is one or more statements that constitute the function body. Because
it doesn’t include a function name, a function literal is
“lost” unless we store it in a variable (or an array
element or object property). We can store a function literal in a
variable for later access, like this:
// Store a function literal in a variable var mouseCoords = function ( ) { return [ _xmouse, _ ymouse ]; }; // Now we can execute the function mouseCoords( );
Note that because ActionScript does not support JavaScript’s
Function( )
constructor, dynamic functions
cannot be composed at runtime, as they can in JavaScript.
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