使用forEach方法更改项目的属性（javascript）(Change Properties of Items using a forEach Method (javascript))

 我正在使用javascript forEach方法迭代数组中的项目，但是当我尝试使用项目执行某些操作时，它会引发错误。 
 
 在下面的代码中，当我使用控制台登录'item'时，它会给控制台记录'div1，div2，div3'所需的行为。 但是，当我尝试对这些项目进行更改时，它将不允许这样做。 在Google中使用forEach方法的例子非常抽象。 
 
 如何使用此方法更改项目的背景颜色或其他属性？ 
 
 Codepen链接在这里https://codepen.io/emilychews/pen/boJBKB 
 
 JS 
 
var div1 = document.getElementById('div1');
var div2 = document.getElementById('div2');
var div3 = document.getElementById('div3');

var myArray = ['div1','div2','div3']

myArray.forEach(function(item){

  console.log(item);

  item.style.backgroundColor = "blue";  

})
 
 CSS 
 
.div {height: 50px; width: 50px; background-color: red; margin-bottom: 10px;}
 
 HTML 
 
<div class="div" id="div1"></div>
<div class="div" id="div2"></div>
<div class="div" id="div3"></div>
 
 任何帮助都是极好的 
 
 艾米莉 

I'm using a javascript forEach method to iterate over items in an array, but it's throwing an error when I try and do something with the items.
 
In the code below when I console log 'item' it gives the desired behavior of logging 'div1, div2, div3' to the console. However, when I try and make a change to these items it won't allow it. The examples of using a forEach method in JS when you Google it is very abstract.
 
How do I use this method to change the background colors or other properties of the items?
 
Codepen link is here https://codepen.io/emilychews/pen/boJBKB 
 
JS
 
var div1 = document.getElementById('div1');
var div2 = document.getElementById('div2');
var div3 = document.getElementById('div3');

var myArray = ['div1','div2','div3']

myArray.forEach(function(item){

  console.log(item);

  item.style.backgroundColor = "blue";  

})
 
CSS
 
.div {height: 50px; width: 50px; background-color: red; margin-bottom: 10px;}
 
HTML
 
<div class="div" id="div1"></div>
<div class="div" id="div2"></div>
<div class="div" id="div3"></div>
 
Any help would be awesome
 
Emily

原文：https://stackoverflow.com/questions/46868297