What are the significant differences among $(sel).bind(“click”, $(sel).click(, $(sel).live(“click”, $(sel).on(“click”?

bind() was added in 1.0, live() in 1.3, delegate() in 1.4.2 and on() in 1.7.

As of 1.7 on() is the preferred use and live() is deprecated and not recommended at all.
If you are using 1.3 use bind() instead of live() and as of 1.4.2 use delegate() instead of live() and as of 1.7 use on() instead of any of the others.

Regarding $("selector").click. Taken from the click() documentation:

In the first two variations, this method is a shortcut for
.bind(“click”, handler), as well as for .on(“click”, handler) as of
jQuery 1.7. In the third variation, when .click() is called without
arguments, it is a shortcut for .trigger(“click”).

Why use on() instead of the others?
on() is the latest addition, joining the jQuery library in version 1.7. on() has several method signatures enabling it to deliver the same results previous version do but improved and optimised. To quote from the documentation:

As of jQuery 1.7, the .on() method provides all functionality required
for attaching event handlers.

There is bascialy no need to use bind() or delegate() anymore. Sure it will work and there should be no harm in using those methods but I would always assume that the latest additions are optimised and improved on any of the drawbacks of previous versions (unless otherwise stated by the documentation as it is in the case of live()).
Based on that I would recommend to use on() instead.

The reason live() is not recommended full-stop is more to do with it’s drawbacks. To quote from the live() documentation.

Use of the .live() method is no longer recommended since later
versions of jQuery offer better methods that do not have its
drawbacks. In particular, the following issues arise with the use of
.live():

  • jQuery attempts to retrieve the elements specified by the selector
    before calling the .live() method, which may be time-consuming on
    large documents.
  • Chaining methods is not supported. For example, $(“a”).find(“.offsite, .external”).live( … ); is not valid and does
    not work as expected.
  • Since all .live() events are attached at the document element, events
    take the longest and slowest possible path before they are handled.
  • On mobile iOS (iPhone, iPad and iPod Touch) the click event does not
    bubble to the document body for most elements and cannot be used with
    .live() without applying one of the following workarounds:

    1. Use natively clickable elements such as a or button, as both of these
      do bubble to document.
    2. Use .on() or .delegate() attached to an element below the level of document.body,
      since mobile iOS does bubble within the body.
    3. Apply the CSS style cursor:pointer to the element that needs to bubble
      clicks (or a parent including document.documentElement). Note however,
      this will disable copy\paste on the element and cause it to be
      highlighted when touched.
  • Calling event.stopPropagation() in the event handler is ineffective in
    stopping event handlers attached lower in the document; the event has
    already propagated to document.
  • The .live() method interacts with other event methods in ways that can
    be surprising, e.g., $(document).unbind(“click”) removes all click
    handlers attached by any call to .live()!

There is a lot more goodies in the documentation though.

Additional Resources
click()
bind()
live() (don’t use)
delegate()
on()

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