When I try to set a text input to blank (when clicked) using $(this).value="", this does not work. I have to use $(this).val('').
Why? What is the difference? What is the mechanism behind the val function in jQuery?
$(document).ready(function() {$('#user_name').focus(function(){$(this).val('');});});// error code: not working...$(document).ready(function() {$('#user_name').focus(function(){$(this).value='';});});Best Answer
You want:
this.value = ''; // straight JS, no jQueryor
$(this).val(''); // jQueryWith $(this).value = '' you're assigning an empty string as the value property of the jQuery object that wraps this -- not the value of this itself.
$(this).value is attempting to call the 'value' property of a jQuery object, which does not exist. Native JavaScript does have a 'value' property on certain HTML objects, but if you are operating on a jQuery object you must access the value by calling $(this).val().
Note that :
typeof $(this) is JQuery object.
and
typeof $(this)[0] is HTMLElement object
then :if you want to apply .val() on HTMLElement , you can add this extension .
HTMLElement.prototype.val=function(v){if(typeof v!=='undefined'){this.value=v;return this;}else{return this.value}}Then :
document.getElementById('myDiv').val() ==== $('#myDiv').val()And
document.getElementById('myDiv').val('newVal') ==== $('#myDiv').val('newVal')العكس INVERSE :
Converselyو if you want to add value property to jQuery object , follow those steps :
Download the full source code (not minified) i.e: example http://code.jquery.com/jquery-1.11.1.js .
Insert Line after L96 , add this code
value:""to init this new prop
Search on
jQuery.fn.init, it will be almost Line 2747
- Now , assign a value to
valueprop : (Before return statment addthis.value=jQuery(selector).val())
Enjoy now : $('#myDiv').value
One thing you can do is this:
$(this)[0].value = "Something";This allows jQuery to return the javascript object for that element, and you can bypass jQuery Functions.