basic javascript issue_问答_开发者_运维开发者技术经验分享

开发者 https://www.devze.com 2023-01-17 05:16 出处：网络

I have a webpage form with a checkbox on it.I am trying to set the box to checked clicking anthat exists on another part of the webpage using the onclick.

相关专题：javascript

I have a webpage form with a checkbox on it. I am trying to set the box to checked clicking an that exists on another part of the webpage using the onclick.

NONE of these seem to work (form and checkbox ID/NAME are all set properly):

 <a href="#" onclick="document.getElementById('frmEditBasicBasic').active.checked=TRUE;"> test </a>

 <a href="#" onclick="document.frmEditBasicBasic.active.checked=TRUE;"> test </a>

 <a href="#" onclick="document.getElementById('active').checked=TRUE;"> test </a>

<a href="#" onclick="window.document.getElementById('frmEditBasicBasic').active.checked=TRUE;"> test </a>

<a href="#" onclick="window.document.frmEditBasicBasic.active.checked=TRUE;"> test </a>

 <a href="#" onclick="window.document.getElementById('active'开发者_如何学JAVA).checked=TRUE;"> test </a>

You should use the <label> element instead:

<label for="active">Test</label>

Clicking this <label> will automatically toggle the checkbox with ID active. (If it's a textbox, it will focus the textbox)

To answer the question, TRUE should be lowercase. (Javascript is case-sensitive)

You should use <label> for the job:

<label for="name">Name</label>
...
<input type="checkbox" id="name" name="name" />

<label><input type="checkbox" id="name" name="name" /> Name</label>

Edit

If you really want to use Javascript to do something special, you need to add return false; to the onclick event, to prevent the browser from changing page. Here is a Javascript example (I never use inline Javascript):

document.getElementById('somelink').onclick = function(){
    document.getElementById('somecheckbox').checked = false; // Unchecks the checkbox
    return false; // Prevents the browser from changing page
};

This works fine: (http://jsfiddle.net/NQ5Rm/4/)

<input type="checkbox" id="active" >

<a href="#" onclick="document.getElementById('active').checked=true;"> test </a>

JavaScript is case-sensitive, and its boolean literals are lower-case. Try obj.checked=true instead. In addition, in some browsers (e.g. Chrome) getElementById() means no more than what it says: It gets element by ID, not by name. Set the id property as well as the name property.

The following works fine for me in IE and Chrome:

 <body>
  <a href="#" onclick="document.getElementById('active').checked=true;"> test </a>
  <form>
    <input type="checkbox" name="active" id="active" value="Car" />
  </form>
 </body>

Some or all of your other versions will probably work equally well, if you fix the capitalization and (if you're not using IE) set id="foo" as well as name="foo" (and if you ARE using IE, bear in mind that most of us aren't).

Lastly, the <label> thing suggested by other commenters is worth knowing, and will probably solve your problem better than the JavaScript.