javascript - 如何在Javascript中循环键入/值对象？ [重复](How to loop through key/value object in Javascript? [duplicate])

Question

This question already has an answer here:

(这个问题在这里已有答案：)

• For..In loops in JavaScript - key value pairs 15 answers

  (For..In中的JavaScript循环 - 键值对 15答案)

var user = {};

now I want to create a setUsers() method that takes a key/value pair object and initializes the user variable.

(现在我想创建一个setUsers()方法，它接受一个键/值对对象并初始化user变量。)

setUsers = function(data) {     
   // loop and init user    
}

where data is like:

(数据如下：)

234: "john", 23421: "smith", ....

  ask by Blankman translate from so

Answer 1

Beware of properties inherited from the object's prototype (which could happen if you're including any libraries on your page, such as older versions of Prototype).

(注意从对象原型继承的属性（如果您在页面上包含任何库，可能会发生这种情况，例如旧版本的Prototype）。)

You can check for this by using the object's hasOwnProperty() method.

(您可以使用对象的hasOwnProperty()方法来检查这一点。)

This is generally a good idea when using for...in loops:

(当使用for...in循环时，这通常是一个好主意：)

var user = {};

function setUsers(data) {
    for (var k in data) {
        if (data.hasOwnProperty(k)) {
           user[k] = data[k];
        }
    }
}