Inside JavaScript

The function Operator

Besides the Function object, JavaScript also supports a function operator . Following the lead of languages such as Perl and Java, the function operator enables you to define a function without a namethat is, an anonymous function. Here's the syntax of this statementnote how much this works like just assigning a function definition to a variable:

var variableName = function([ parameter1 [, parameter2 ...[, parameterN ]]]) { functionBody }

As you see in Table 3.14, the function operator is fairly recent.

Table 3.14. The function Operator

Operator

NS2

NS3

NS4

NS6

IE3a

IE3b

IE4

IE5

IE5.5

IE6

function

     

x

       

x

x

The syntax for using this operator is much like that for using the Function object. Here's an example putting this operator to work, where I'm setting up a function to double the number you pass it, and assigning that function to a variable named doubler :

(Listing 03-15.html on the web site)

<HTML> <HEAD> <TITLE> Passing Data to Functions </TITLE> </HEAD> <BODY> <H1>Passing Data to Functions</H1> <SCRIPT LANGUAGE="JavaScript"> <!-- var doubler = function(operand1) {return 2 * operand1} document.write("2 * 10 = " + doubler(10)) // --> </SCRIPT> </BODY> </HTML>

Figure 3.12 shows the results of this code.

Figure 3.12. Using the function operator.

Related

Категории