我一直在玩 codepen.io,遇到了这个我无法解决的特殊问题。
我的以下笔在 codepen 中不起作用,但在我的机器上本地工作,我不确定我是否需要做一些额外的事情或启用 codepen 上的功能才能使其工作。
任何帮助最受赞赏:)
HTML
<span>Background color:</span>
<select id="background">
<option value="Red">Red</option>
<option value="Green">Green</option>
<option value="Blue">Blue</option>
</select>
<span>Width:</span>
<select id="width">
<option value="100px">100px</option>
<option value="200px">200px</option>
<option value="300px">300px</option>
</select>
<span>height:</span>
<select id="height">
<option value="100px">100px</option>
<option value="200px">200px</option>
<option value="300px">300px</option>
</select>
<br/>
<br/>
<div id="content" style="background:red; width:100px; height:100px;"></div>
JS
// array of virtual DOM objects
var arraySelect = document.getElementsByTagName('select');
var content = document.getElementById('content');
// function
function dropdownStyles() {
// apply the value from the select options (when applied) has the style values for content.
var style = this.id;
var value = this.value;
content.style[style] = value;
}
// create a loop to iterate each select option in document add an event listener to each.
for( var i = 0; i < arraySelect.lenght; i++ ){
// with dropdownStyles() the function will get executed so that is why we don't add the brackets
arraySelect[i].addEventListener('change',dropdownStyles);
}