一、结合判断的依据是
- 由于typeof只能判断类型，所以，数组和对象返回的都是object，这时就需要使用instanceof来判断了
二、代码如下
function getType(obj) {
if (obj === null) {
return null;
} else if (typeof obj === "object") {
if(obj instanceof Array) return "array";
else return "object"
} else {
return typeof obj;
}
}
三、测试
console.log(getType(111)); //number
console.log(getType("fasd"));//string
console.log(getType(true));//boolean
console.log(getType(function () { }));//function
console.log(getType([]));//array
console.log(getType({}));//object
console.log(getType(null));//null
console.log(getType(undefined));//undefined
console.log(getType(/\n/));//object
console.log(getType());//undefined
