How to use the Function function for getting started with js

In JavaScript, functions can be nested.

　For example:

function(){

　　funcrion square(x){ return x*x; }

　　return square(10);

}

In JavaScript, a function is bound to an object, and the function called by the object is called a method, which is easy to be confused with C#.

1. Function attributes

In the function body, you can get the number of actual parameters passed into the function through arguments.length.

function fun1 (x,y){

　　document.write(arguments.length());　　//输出2，传入的参数是两个
}
fun1();

2. Bind the function to the object

var fun1 = function () {
 alert(this.name);
}
var o = { name:"张三",fn : fun1 };
o.fn();　　//输出 张三
var o = { name: "张三", fn: function () { alert(this.name) } }
o.fn();　　//输出张三