//方法一使用typeof方法。
console.log(typeof str);//string
console.log(typeof arr);//object
console.log(typeof obj);//object
console.log(typeof num);//number
console.log(typeof b);//boolean
console.log(typeof n);//null是一个空的对象
console.log(typeof u);//undefined
console.log(typeof fn);//function
console.log(o instanceof Object);// true
console.log(a instanceof Array);// true
console.log(o instanceof Array);// false
console.log(o.constructor == Object);//true
console.log(a.constructor == Array);//true
console.log(Object.prototype.toString.call(a));//[object Array]
console.log(Object.prototype.toString.call(o));//[object Object]
console.log(Object.prototype.toString.call(c));//[object Function]
console.log(Object.prototype.toString.call(new c));//[object Object]
//封装一个方法判断数组和对象
function isType(obj){ var type = Object.prototype.toString.call(obj); if(type == '[object Array]'){ return 'Array'; }else if(type == '[object Object]'){ return "Object" }else{ return 'param is no object type'; } }
console.log(isType(o));//Object
console.log(isType(a));//Array
//下面是更简洁的封装，来自vue源码
var _toString = Object.prototype.toString;
function toRawType (value) {return _toString.call(value).slice(8, -1)}
