Is there a clever (i.e. optimized) way to rename a key in a javascript object?  A non-optimized way would be:  o[ new_key ] = o[ old_key ]; delete o[ old_key ];...

What's the fastest way to count the number of keys/properties of an object?  It it possible to do this without iterating over the object?  i.e. without doing  var count = 0; for (k in myobj) if (myobj.hasOwnProperty(k)) count++;   (Firefox did...

I'm just wondering how to get all key values in localStorage.    I have tried to retrieve the values with a simple JavaScript loop  for (var i=1; i <= localStorage.length; i++)  {    alert(localStorage.getItem(i)) }   But it works only if th...

I hate this mess with the mouse buttons created by W3C an MS! I want to know if the left mouse button is pressed when I get a mousedown event.   I use this code  // Return true if evt carries left mouse button press function detectLeftButton(evt) {...

I'm looking for a KeyListener for a game I'm developing in JavaScript. I have no idea how this would work in real code but it would be something like this:   if(keyPress == upKey) {     playerSpriteX += 10; } else if(keyPress == downKey) {...

I'm not sure what I am doing wrong here. I want the enter key to work as well as clicking the button.  <form action="" method="get" class="priceOptionForm" name="priceOptionForm"> <input name="paypal_e...

Is this allowed?  myObj = {}; myObj['4a56546s6d']   Or the key must start with a letter like:  myObj = {}; myObj['x4a56546s6d']   Can I mix both like:  myObj = {}; myObj['x4a56546s6d'] myObj['4a56546s6d']   I ask that...

I have a Javascript Object that contains a mix of property types including simple strings, objects, arrays of objects... and so on.  I would like to sort the keys following this rule:   'Simple properties like strings or numbers appears always be...

Question is similar to: How can I check that two objects have the same set of property names? but only one difference  I want to check:  var objOne = {"a":"one","b":"two","c":{"f":"three_one"}};...

I am building a autocomplete feature for input text field. Currently I could use mouse click to choose the selection, I'd like to add keyboard control to allow autocomplete control. I monitored the keycode in onkeyup event, it appears for up/down...