单项选择题
以下this指向谁()var obj = { name:"ABC", sayName:()=>{ console.log(this); } }; obj.sayName()
A.windowB.objC.nullD.document
输出的this指向谁()var obj ={ele:document.getElementById("box"...
输出的this指向谁()var obj ={ele:document.getElementById("box"),sayName(){this.ele.onclick=()=>{console.log(this);}}};obj.sayName()
A.windowB.objC.box元素D.null
var t ="";alert(typeof(t))程序的输出结果是()A.undefinedB.nullC....
单项选择题var t ="";alert(typeof(t))程序的输出结果是()
A.undefinedB.nullC.stringD.""
var Run = function(){}____________.print = function(){ ...
var Run = function(){}____________.print = function(){ alert("666");}var obj = new Run();obj.print()横线处补充什么代码, 打印结果是‘666’()
A.Run.prototypeB.RunC.Run.prototype.toStringD.以上都不对