undefined getElementById [英] undefined getElementById

问题描述

为什么

var offer = document.getElementById（" editor_displaying_t ext"）。value;

返回undefined？

谢谢

Why
var offer=document.getElementById("editor_displaying_t ext").value;
returns undefined?
Thank You

推荐答案

为什么

var offer = document.getElementById（" editor_displaying_t ext"） .value;

返回undefined？

谢谢

Why
var offer=document.getElementById("editor_displaying_t ext").value;
returns undefined?
Thank You

如果没有知识真的很难说什么是editor_displaying_text是。


我要继续说不是所有元素都有一个名为value的属性......事实上，大多数元素都没有。除非editor_displaying_text是OBJECT，PARAM，LI，INPUT是对象。或BUTTON，值将返回undefined。


阅读DTD：http：//www.w3.org/TR/html/DTD/xhtml1-transitional.dtd，对值执行CTRL-F并且看看它经常出现的频率......不常见。


您可能想查看childNodes。数组中的元素中的dom元素列表 - 或者，如果您喜欢便宜的&简单的出路，innerHTML。

it''s really hard to tell without knowledge of what "editor_displaying_text" is.

I''m going to go on a limb and say not all elements have a property called "value"... in fact, most do not. Unless "editor_displaying_text" is an "OBJECT", "PARAM", "LI", "INPUT" or "BUTTON", value will return undefined.

Read the DTD: http://www.w3.org/TR/html/DTD/xhtml1-transitional.dtd, do a CTRL-F for "value" and see how often it shows up.... not very often.

You may want to check out the "childNodes" array for a list of dom elements within the element -- or, if you like the cheap & easy way out, innerHTML.

这是一个可编辑的div，id是editor_displaying_text

谢谢你

It''s an editable div which id is editor_displaying_text
Thank You

你''必须显示你的代码。你在哪里定义页面？

You''ll have to show your code. Where do you define it within the page?

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