全局变量遇到的坑

Posted 2020-07-11 还能再菜点吗？

这种情况结果一样
var aname="The Window";   

console.log(aname);//The Window
console.log(window.aname)//The Window


但是写在$(function(){........})中结果不等
$(function(){
var aname="The Window";   

console.log(aname);//The Window
console.log(window.aname)//underfind


});

案例二

var aname="The Window";   
var obj = {   
    aname:"My Object",   
    getNameFunc : function(){  
        return function(){   
            alert(this.aname);   
        };   
    }   
};

obj.getNameFunc()();//The Window

obj.getNameFunc()();//The Window

和

$(function(){

var aname="The Window";   
var obj = {   
    aname:"My Object",   
    getNameFunc : function(){  
        return function(){   
            alert(this.aname);   
        };   
    }   
};

obj.getNameFunc()//这里面的this位window

obj.getNameFunc()();//underfind  })

结果是因为作用于所引起的

详见：http://q.cnblogs.com/q/82633/