Category: JavaScript

If not working with a framework, try the following:

$(function() {
  function MyFunction() {
  }

  MyFunction.prototype = {
    myMethod: function() {
    }
  };

  var myInstance = new MyFunction();
});

If you are looking for something simpler, kind of a one quick page deal:

var GLOBAL_NAMESPACE_HERE = (function () {
    var _private_obj_name_here = {
        // settings and defaults here
        key_here: value_here
    };

    /********************************************************************
     * Initialization:
     * Starts the listeners and get things rolling
    */
    _private_obj_name_here.init = function () {
    };

    /********************************************************************
     * Getters, other stuff
    */
    _private_obj_name_here.getSomething = function () {
        return _private_obj_name_here.key_here;
    };

    /********************************************************************
     * Expose public methods (the ones that can be called from outside)
    */
    return {
        init : _private_obj_name_here.init,
        getSomething: _private_obj_name_here.getSomething
    };

}());

This is called the module pattern.

GLOBAL_NAMESPACE_HERE.init();

if(something){

// Do this

}

Do this will happen, if “something” is equal to:

undefined

null

0 (as in the number)

“” (empty string)

NaN (not a number object)

Be careful! Any kind of object, or even the string “0” will evaluate to true!

The reason stuff like this works:

var myvar = me || you;

is because if “me” evaluates to true, that is what’s returned. Otherwise “you” will. That is assuming we don’t know if “me” or “you” are undefined at the moment.

http://jsfiddle.net/ramiror/fTtUA/ remove markers:

my_marker.setMap(null)

Programatically create a dialog box:

$.mobile.changePage( “page for the dialog content”, { role: “dialog”} );

Sometimes you have to setTimeOut call a function, but you need to provide the current scope for the function to execute as well.

Say for example, you want to call this.myFunction()

with (this) { setTimeout( function() { myFunction() }, 1000 );}

Doing the with(this) allows you to pass “this” scope, so myFunction will get executed as this.myFunction()

There are a million things wrong with doing the above. First, myFunction will try to execute off the Global, also, with is heavy performance-wise. But it works. Use it sparingly.

Attributes:

type: The language your script is in. Defaults to javascript since HTML5. In older browsers you were able to run alt languages, like VBScript in IE. In fact, it is supposed to actually point to the mime type of your script. The syntax is, for example: type=”text/javascript”

language: not used. Deprecated.

async: When set to true, makes the download of the script asynchronous, not holding the page hostage until it downloads. The default is false, so pages have to wait until this downloads before they go on. It is HTML5 supported. Moving scripts at the end of the page is a more compatible technique (with older browsers) to avoid scripts blocking page rendering, but don’t do it if you have document.write commands in your script. (async=”async”)

defer: waits until the DOM is ready before executing the script. It is HTML5 supported. It is overriden by async (defer=”defer”)

XHTML compatibility. If you use that as your doctype, you have to envelop your inline scripts in CDATA, to avoid special characters like & to cause problems:

<script type="text/javascript">
//<![CDATA[
  // Your javascript here
//]]>
</script>

Example of dynamically adding scripts to a document:

var script = document.createElement("script");
script.setAttribute("src", url);
document.head.appendChild(script);