js函数基础知识

var box=function(a,b) {
    return a(b);
}

function a(b){
    return b+10;
}

alert(box(a,3));

function box(num){
    if(num<=1){
        return 1;
    }else{
        return num*arguments.callee(num-1);
    }
}

document.write(box(10));

var box={
    name:"田伟",
    func:function(){
        return this.name;
    }
}

document.write(box.func());//田伟

function box(a,b){
    return a+b;
}
function sum(c,d){
    return box.apply(this,[c,d]);
　　//return box.apply(this,arguments);
}
document.write(sum(3,4));
//冒充box,this表示box在window下面

function box(a,b){
    return a+b;
}
function sum(c,d){
    return box.call(this,c,d);
}
document.write(sum(3,555));

var color="蓝色";
var box={
    color:"红色"
}

function showcolor() {
    return this.color;
}
document.write(showcolor.call(box));