加window 和不加的区别 setInterval()

Question

 function scroll(){
                time1 = window.setInterval(function(){
                all_member.style.top = String(-member_array.length*50)+"px";
                },500)
                time2 = window.setInterval(function(){
                    all_member.style.top = "0px";
                },1000)
        }

 function scroll(){
                time1 = setInterval(function(){
                all_member.style.top = String(-member_array.length*50)+"px";
                },500)
                time2 = setInterval(function(){
                    all_member.style.top = "0px";
                },1000)
        }

写window 和不写有什么区别??

Answer 1

一般来说没区别，在上面的例子中完全没有区别。

写 window 可避免一些命名空间冲突的问题。

Answer 2

对于你的例子是没区别的

我来提供一些特殊的场景吧

window.a = 1;
(function (){
    var a = 2;
    console.log(a, window.a)
})()

//window.a = 1;
(function (){
    var b = 2;
    console.log(b, window.b)
})()

//window.a = 1;
(function (){
    //var c = 2;
    console.log(window.c)
    console.log(c)
})()

Answer 3

https://www.zhihu.com/questio...
参考此答案