typeof和instanceof结合精准判断类型

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