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How to run a function in jquery


Question

I'm a programming newbie, and I can't figure out how to store a function in JQuery and run in it multiple places.

I have:

$(function () {
  $("div.class").click(function(){
    //Doo something

  });

  $("div.secondclass").click(function(){
    //Doo something
  });

});

Now the 2 "//Doo somethings" are the same, and I don't want to write the same code again.

If I put:

$(function () {

  function doosomething ()
  {
    //Doo something
  }

  $("div.class").click(doosomething);

  $("div.secondclass").click(doosomething);

});

That would run the function on page load, rather than only when it clicks.

How do I do this correctly?

Thanks!

2013/05/01
1
63
5/1/2013 1:18:38 AM

Accepted Answer

The following should work nicely.

$(function() {

  // Way 1
  function doosomething()
  {
    //Doo something
  }

  // Way 2, equivalent to Way 1
  var doosomething = function() {
    // Doo something
  }

  $("div.class").click(doosomething);

  $("div.secondclass").click(doosomething);

});

Basically, you are declaring your function in the same scope as your are using it (JavaScript uses Closures to determine scope).

Now, since functions in JavaScript behave like any other object, you can simply assign doosomething as the function to call on click by using .click(doosomething);

Your function will not execute until you call it using doosomething() (doosomething without the () refers to the function but doesn't call it) or another function calls in (in this case, the click handler).

2009/07/28
110
7/28/2009 3:43:50 AM

I would do it this way:

(function($) {
jQuery.fn.doSomething = function() {
   return this.each(function() {
      var $this = $(this);

      $this.click(function(event) {
         event.preventDefault();
         // Your function goes here
      });
   });
};
})(jQuery);

Then on document ready you can do stuff like this:

$(document).ready(function() {
   $('#div1').doSomething();
   $('#div2').doSomething();
});
2009/07/28

function doosomething ()
{
  //Doo something
}


$(function () {


  $("div.class").click(doosomething);

  $("div.secondclass").click(doosomething);

});
2011/11/15

Alternatively (I'd say preferably), you can do it like this:

$(function () {
  $("div.class, div.secondclass").click(function(){
    //Doo something
  });
});
2009/07/28

You can also do this - Since you want one function to be used everywhere, you can do so by directly calling JqueryObject.function(). For example if you want to create your own function to manipulate any CSS on an element:

jQuery.fn.doSomething = function () {
   this.css("position","absolute");
   return this;
}

And the way to call it:

$("#someRandomDiv").doSomething();
2012/10/09

Is this the most obfuscated solution possible? I don't believe the idea of jQuery was to create code like this.There's also the presumption that we don't want to bubble events, which is probably wrong.

Simple moving doosomething() outside of $(function(){} will cause it to have global scope and keep the code simple/readable.

2012/07/14

Source: https://stackoverflow.com/questions/1191833
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