var show=function (x) { console.log(typeof x); // undefined console.log(typeof 10); // number console.log(typeof 'abc'); // string console.log(typeof true); // boolean console.log(typeof function () {}); //function console.log(typeof [1, 'a', true]); //object console.log(typeof { a: 10, b: 20 }); //object console.log(typeof null); //object console.log(typeof new Number(10)); //object return 1; } console.log( show instanceof Object) console.log( show()) var fn=function(){} console.log( fn instanceof Object)
var dd="就ask打开"; console.log(isNaN( parseInt(dd)));