constructor object的区别

var obj = {};
obj.constructor //? Object() { [native code] }
obj.constructor == Object //true
var arr = [];
arr.constructor //? Array() { [native code] }
arr.constructor == Array //true
function Fun(){
console.log(‘function‘);
}
var fun = new Fun(); //实例化
fun.constructor //? Fun(){console.log(‘function‘)} 【打印出来的引用是Fun函数，说明fun的引用是Fun函数】
Fun.constructor //? Function() { [native code] } 【打印出来的引用是Funcion函数，说明Fun的引用是Function函数】
fun.constructor == Fun //true 【再次证明fun的constructor属性引用了fun对象的构造函数】
fun.constructor == Fun.constructor //false

function isArray (val){
var isTrue = typeof val == ‘object‘ && val.constructor == Array;
return isTrue?true:false;
}
var arr = isArray([1,2,3,4,5]);
console.log(arr); //true