js中的typeof和instanceof和===的区别

//五种基本类型

    var num=1;    var str="abc";    var bl=true;    var nu=null;    var undef=undefined;    //三种特殊类型

    var obj=new Object();    var arr2=["1",2,true];    var fun=function () {

    }

    write("-------typeof-----------")

    write(num,typeof num);//1 number

    write(str,typeof str);//abc string

    write(bl,typeof bl);//true boolean

    write(nu,typeof nu);//null object

    write(undef,typeof undef)//undefined undefined

    write(obj,typeof obj);//[object Object] object

    write(arr2,typeof arr2);//1,2,true object

    write("-----------===-----------")

    write(num,typeof num==="number");//1 true

    write(str,typeof str==="string");//abc true

    write(bl,typeof bl==="boolean");//true true

    write(nu,typeof nu==="object");//null true

    write(undef,typeof undef==="undefined")//undefined true

    write(obj,typeof obj==="object");//[object Object] true

    write(arr2,typeof arr2==="object");//1,2,true true

    write(fun,typeof fun==="function");//function () { } true

    write("---------instanceof---------------")

    write(obj,obj instanceof Object)//[object Object] true

    write(arr2,arr2 instanceof Array);//1,2,true true

    write(arr2,arr2 instanceof Object);//1,2,true true

    write(fun, fun instanceof Function)//function () { } true

    write(fun, fun instanceof Object)//function () { } true