js Function reference in some types of common and useful methods and properties

Function type

Because it is an instance of function Function type, the function name is a pointer to a function object, not a function connected tightly together, which led to the js not really overloaded, but the advantage is, function objects can be an argument to a function or return value;

Instead of performing the function pointer to access a function object itself can not be bracketed

var func = new Function("x", "y", "return x + y");// 构造函数来实例化一个Function类型, 但不推荐使用
function func(x, y){
    return x + y;
}// 函数声明 js引擎会将所有的函数声明提升到顶部
var func = function (x, y){ return x + y };// 函数表达式 变量的赋值, 变量func保存着 function(x, y){ return x + y} 这个对象

Function type, there are two special objects: arguments and this, in the former which has passed into the function of all parameters, there is a callee property, which is a pointer to the instance has this property Function; and the this pointer to the execution environment , which is an example of Global type. is a window in your browser.

function b(){
    console.log(arguments.callee);
}

Function type properties and methods

length // Funciton实例期望接收形式参数的个数
prototype // 

apply();// 非继承的方法  
// apply(Function实例运行的作用域:this, Array实例或arguments)

call();//  非继承的方法
// call(Function实例运行的作用域:this, arg1, arg2, ...)

//

bind( X );// 将Function的实例的this指向 对象 X

In addition, Function There is also a special type of property: caller, this is a pointer, it can not be assigned to this property in strict mode.

Function Type Function One example of a type of a call to another instance b, then the caller attribute instance b will instance a point;

function a(){
    b();
}
function b(){
    console.log(arguments.callee.caller);
}