写一个函数去判断数据类型

判断数据类型

function judgeType(ele){
    let res = typeof ele;
    if(res === "object"){
        // 短路表达式，第一个成立则返回第二个的值，第一个不成立，则返回第一个的值
        Object.prototype.toString.call(ele) === "[object Object]" && (res = "object");
        Object.prototype.toString.call(ele) === "[object Array]" && (res = "array");
        Object.prototype.toString.call(ele) === "[object Date]" && (res = "date");
        Object.prototype.toString.call(ele) === "[object Null]" && (res = "null");
        Object.prototype.toString.call(ele) === "[object RegExp]" && (res = "RegExp");
    }
    return res;
}
// ----------一般数据类型---------
console.log(judgeType(23));     //  number
console.log(judgeType(false));     //  boolean
console.log(judgeType("23"));   // string
console.log(judgeType(undefined));//    undefined
console.log(judgeType(NaN));    //  number
console.log(judgeType(function (){}));  // function

console.log("===============================");
// ---------- 对象类型数据---------
console.log(judgeType(null));   // object   null
console.log(judgeType({}));     // object   object
console.log(judgeType([]));     // object   array
console.log(judgeType(new Date()));     // object   date
console.log(judgeType(new RegExp()));     // object RegExp

写一个函数去判断数据类型

原文：https://www.cnblogs.com/fuct/p/15226457.html