js类型有:字符串、数字、布尔、数组、对象、null、undefined。
typeof
console.log(typeof "a"); //string console.log(typeof 1); //number console.log(typeof true); //boolean console.log(typeof []); //object console.log(typeof new {}); //object console.log(typeof null); //object var a; console.log(typeof a); //undefined console.log(typeof function(){}); //function
从中可以看出typeof对数组、对象、null返回的类型都为object。
Object.prototype.toString.call
var type=Object.prototype.toString; console.log(type.call("a")); //[object String] console.log(type.call(1)); //[object Number] console.log(type.call(true)); //[object Boolean] console.log(type.call([])); //[object Array] console.log(type.call({})); //[object Object] console.log(type.call(null)); //[object Null] var a; console.log(type.call(a)); //[object Undefined] console.log(type.call(function(){})); //[object Function]
时间: 2024-09-30 07:15:04