jQuery .on('click') vs. .click() and .delegate('click')

Both modes are still supported.

The following call to bind():

$(".foo").bind("click", function() {
    // ...
});

Can be directly converted into the following call to on():

$(".foo").on("click", function() {
    // ...
});

And the following call to delegate():

$("#ancestor").delegate(".foo", "click", function() {
    // ...
});

Can be converted into the following call to on():

$("#ancestor").on("click", ".foo", function() {
    // ...
});

For completeness, the following call to live():

$(".foo").live("click", function() {
    // ...
});

Can be converted into the following call to on():

$(document).on("click", ".foo", function() {
    // ...
});

---

UPDATE:

Except on event, the rest of the events were deprecated in different jQuery versions.

• bind - version deprecated: 3.0
• live - version deprecated: 1.7, removed: 1.9
• delegate - version deprecated: 3.0

The on method can replace both bind and delegate depending on how it's used (and also click as bind can replace that):

.click(handler) == .on('click', handler)

.bind('click', handler) ==  .on('click', handler)

.delegate('click', '#id', handler) == .on('click', '#id', handler)

Neither the click, delegate or bind methods have made it to the deprecated page yet. I doubt that the click method ever will.

You can deduce the usage for the aliases from the source code.

console.log($.fn.delegate);
function (a, b, c, d) {
    return this.on(b, a, c, d);
}

console.log($.fn.bind);
function (a, b, c) {
    return this.on(a, null, b, c);
}

The documentation also provides the usage examples:

$(elements).delegate(selector, events, data, handler);  // jQuery 1.4.3+
$(elements).on(events, selector, data, handler);        // jQuery 1.7+