working - javascript:void(0) alternative




Which “href” value should I use for JavaScript links, “#” or “javascript:void(0)”? (20)

The following are two methods of building a link that has the sole purpose of running JavaScript code. Which is better, in terms of functionality, page load speed, validation purposes, etc.?

function myJsFunc() {
    alert("myJsFunc");
}
<a href="#" onclick="myJsFunc();">Run JavaScript Code</a>

or

function myJsFunc() {
    alert("myJsFunc");
}
 <a href="javascript:void(0)" onclick="myJsFunc();">Run JavaScript Code</a>

# is better than javascript:anything, but the following is even better:

HTML:

<a href="/gracefully/degrading/url/with/same/functionality.ext" class="some-selector">For great justice</a>

JavaScript:

$(function() {
    $(".some-selector").click(myJsFunc);
});

You should always strive for graceful degradation (in the event that the user doesn't have JavaScript enabled...and when it is with specs. and budget). Also, it is considered bad form to use JavaScript attributes and protocol directly in HTML.


'#' will take the user back to the top of the page, so I usually go with void(0).

javascript:; also behaves like javascript:void(0);


Definitely hash (#) is better because in JavaScript it is a pseudoscheme:

  1. pollutes history
  2. instantiates new copy of engine
  3. runs in global scope and doesn't respect event system.

Of course "#" with an onclick handler which prevents default action is [much] better. Moreover, a link that has the sole purpose to run JavaScript is not really "a link" unless you are sending user to some sensible anchor on the page (just # will send to top) when something goes wrong. You can simply simulate look and feel of link with stylesheet and forget about href at all.

In addition, regarding cowgod's suggestion, particularly this: ...href="javascript_required.html" onclick="... This is good approach, but it doesn't distinguish between "JavaScript disabled" and "onclick fails" scenarios.


Depending on what you want to accomplish, you could forget the onclick and just use the href:

<a href="javascript:myJsFunc()">Link Text</a>

It gets around the need to return false. I don't like the # option because, as mentioned, it will take the user to the top of the page. If you have somewhere else to send the user if they don't have JavaScript enabled (which is rare where I work, but a very good idea), then Steve's proposed method works great.

<a href="javascriptlessDestination.html" onclick="myJSFunc(); return false;">Link text</a>

Lastly, you can use javascript:void(0) if you do not want anyone to go anywhere and if you don't want to call a JavaScript function. It works great if you have an image you want a mouseover event to happen with, but there's not anything for the user to click on.


I agree with suggestions elsewhere stating that you should use regular URL in href attribute, then call some JavaScript function in onclick. The flaw is, that they automaticaly add return false after the call.

The problem with this approach is, that if the function will not work or if there will be any problem, the link will become unclickable. Onclick event will always return false, so the normal URL will not be called.

There's very simple solution. Let function return true if it works correctly. Then use the returned value to determine if the click should be cancelled or not:

JavaScript

function doSomething() {
    alert( 'you clicked on the link' );
    return true;
}

HTML

<a href="path/to/some/url" onclick="return !doSomething();">link text</a>

Note, that I negate the result of the doSomething() function. If it works, it will return true, so it will be negated (false) and the path/to/some/URL will not be called. If the function will return false (for example, the browser doesn't support something used within the function or anything else goes wrong), it is negated to true and the path/to/some/URL is called.


I believe you are presenting a false dichotomy. These are not the only two options.

I agree with Mr. D4V360 who suggested that, even though you are using the anchor tag, you do not truly have an anchor here. All you have is a special section of a document that should behave slightly different. A <span> tag is far more appropriate.


I recommend using a <button> element instead, especially if the control is supposed to produce a change in the data. (Something like a POST.)

It's even better if you inject the elements unobtrusively, a type of progressive enhancement. (See this comment.)


I tried both in google chrome with the developer tools, and the id="#" took 0.32 seconds. While the javascript:void(0) method took only 0.18 seconds. So in google chrome, javascript:void(0) works better and faster.


I use the following

<a href="javascript:;" onclick="myJsFunc();">Link</a>

instead

<a href="javascript:void(0);" onclick="myJsFunc();">Link</a>

I usually go for

<a href="javascript:;" onclick="yourFunction()">Link description</a>

It's shorter than javascript:void(0) and does the same.


I would use:

<a href="#" onclick="myJsFunc();return false;">Link</a>

Reasons:

  1. This makes the href simple, search engines need it. If you use anything else ( such as a string), it may cause a 404 not found error.
  2. When mouse hovers over the link, it doesn't show that it is a script.
  3. By using return false;, the page doesn't jump to the top or break the back button.

I'd say the best way is to make an href anchor to an ID you'd never use, like #Do1Not2Use3This4Id5 or a similar ID, that you are 100% sure no one will use and won't offend people.

  1. Javascript:void(0) is a bad idea and violates Content Security Policy on CSP-enabled HTTPS pages https://developer.mozilla.org/en/docs/Security/CSP (thanks to @jakub.g)
  2. Using just # will have the user jump back to the top when pressed
  3. Won't ruin the page if JavaScript isn't enabled (unless you have JavaScript detecting code
  4. If JavaScript is enabled you can disable the default event
  5. You have to use href unless you know how to prevent your browser from selecting some text, (don't know if using 4 will remove the thing that stops the browser from selecting text)

Basically no one mentioned 5 in this article which I think is important as your site comes off as unprofessional if it suddenly starts selecting things around the link.


Ideally you'd do this:

<a href="javascriptlessDestination.html" onclick="myJSFunc(); return false;">Link text</a>

Or, even better, you'd have the default action link in the HTML, and you'd add the onclick event to the element unobtrusively via JavaScript after the DOM renders, thus ensuring that if JavaScript is not present/utilized you don't have useless event handlers riddling your code and potentially obfuscating (or at least distracting from) your actual content.


If there is no href maybe there is no reason to use an anchor tag.

You can attach events (click, hover, etc.) on almost every element, so why not just use a spanor a div?

And for users with JavaScript disabled: if there isn't a fallback (for example, an alternative href), they should at least not be able to see and interact with that element at all, whatever it is an <a> or a <span> tag.


It would be better to use jQuery,

$(document).ready(function() {
    $("a").css("cursor", "pointer");
});

and omit both href="#" and href="javascript:void(0)".

The anchor tag markup will be like

<a onclick="hello()">Hello</a>

Simple enough!


Neither if you ask me;

If your "link" has the sole purpose of running some JavaScript code it doesn't qualify as a link; rather a piece of text with a JavaScript function coupled to it. I would recommend to use a <span> tag with an onclick handler attached to it and some basic CSS to immitate a link. Links are made for navigation, and if your JavaScript code isn't for navigation it should not be an <a> tag.

Example:

function callFunction() { console.log("function called"); }
.jsAction {
    cursor: pointer;
    color: #00f;
    text-decoration: underline;
}
<p>I want to call a JavaScript function <span class="jsAction" onclick="callFunction();">here</span>.</p>

So, when you are doing some JavaScript things with an <a /> tag and if you put href="#" as well, you can add return false at the end of the event (in case of inline event binding) like:

<a href="#" onclick="myJsFunc(); return false;">Run JavaScript Code</a>

Or you can change the href attribute with JavaScript like:

<a href="javascript://" onclick="myJsFunc();">Run JavaScript Code</a>

or

<a href="javascript:void(0)" onclick="myJsFunc();">Run JavaScript Code</a>

But semantically, all the above ways to achieve this are wrong (it works fine though). If any element is not created to navigate the page and that have some JavaScript things associated with it, then it should not be a <a> tag.

You can simply use a <button /> instead to do things or any other element like b, span or whatever fits there as per your need, because you are allowed to add events on all the elements.


So, there is one benefit to use <a href="#">. You get the cursor pointer by default on that element when you do a href="#". For that, I think you can use CSS for this like cursor:pointer; which solves this problem also.

And at the end, if you are binding the event from the JavaScript code itself, there you can do event.preventDefault() to achieve this if you are using <a> tag, but if you are not using a <a> tag for this, there you get an advantage, you don't need to do this.

So, if you see, it's better not to use a tag for this kind of stuff.


The first one, ideally with a real link to follow in case the user has JavaScript disabled. Just make sure to return false to prevent the click event from firing if the JavaScript executes.

<a href="#" onclick="myJsFunc(); return false;">Link</a>

If you use Angular2, this way works:

<a [routerLink]="" (click)="passTheSalt()">Click me</a>.

See here https://.com/a/45465728/2803344


Using just # makes some funny movements, so I would recommend to use #self if you would like to save on typing efforts of JavaScript bla, bla,.


Usually, you should always have a fall back link to make sure that clients with JavaScript disabled still has some functionality. This concept is called unobtrusive JavaScript.

Example... Let's say you have the following search link:

<a href="search.php" id="searchLink">Search</a>

You can always do the following:

var link = document.getElementById('searchLink');

link.onclick = function() {
    try {
        // Do Stuff Here        
    } finally {
        return false;
    }
};

That way, people with JavaScript disabled are directed to search.php while your viewers with JavaScript view your enhanced functionality.





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