Created
July 9, 2014 14:05
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变量的类型检查方式
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/** | |
* | |
* js的类型检测方式->typeof、constuctor。 | |
* 推荐通过构造函数来检测变量的类型。 | |
*/ | |
var obj = {key:'value'}, | |
arr = ["hello","javascript"], | |
fn = function(){}, | |
str = "hello js", | |
num = 55, | |
bool = true, | |
User = function(){}, | |
user = new User(); | |
/*typeof测试*/ | |
console.log(typeof obj); //obj | |
console.log(typeof arr); //obj | |
console.log(typeof fn); //function | |
console.log(typeof str); //string | |
console.log(typeof num); //number | |
console.log(typeof bool); //boolean | |
console.log(typeof user); //object | |
/*constructor测试*/ | |
console.log(obj.constructor == Object); //true | |
console.log(arr.constructor == Array); //true | |
console.log(str.constructor == String); //true | |
console.log(num.constructor == Number); //true | |
console.log(bool.constructor == Boolean);//true | |
console.log(user.constructor == User); //true |
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