I have following object:
$("input:checkbox:checked")
[
<input class="li_checker" type="checkbox" category_uid="1.3" category_language="da">,
<input class="li_checker" type="checkbox" category_uid="1.3.1" category_language="da">
]
If there is any helper in jQuery which allows me to get value of "category_uid" for all elements and returns it as the another array? Expected result:
["1.3", "1.3.1"]
Use map():
var myArray = $("input:checkbox:checked").map(function(){
return this.getAttribute("category_uid");
}).get();
map doesn't return an array, it returns a jQuery wrapper around an array. You have to use .get() to get the actual array.
As bpierre suggested, use .map(). His answer is correct.
If you need this behavior for different attributes, you might as well write is as a reusable function (“jQuery plugin”):
jQuery.fn.pluck = function(attr) {
return this.map(function() {
return this.getAttribute(attr);
}).get();
};
$('input:checkbox:checked').pluck('category_uid'); // ["1.3", "1.3.1"]
P.S. category_uid is not a valid attribute in HTML. Consider using custom data-* attributes instead, e.g. data-category-uid="foo".
Just for the fun of it, a third way, this one using attr:
var categories = [];
$("input:checkbox:checked").attr("category_uid", function(index, value) {
categories.push(value);
});
Off-topic: If you want to have arbitrary, custom attributes on HTML elements, recommend using the data- prefix defined by HTML5 (details). You can use it now, even if you're not using the HTML5 doctype (this is one of the places where HTML5 is just codifying — and reining in — current practice), and it future-proofs a bit.
undefined). So I've logged a ticket to document it (or not, of course, if it's not desired behavior).var myarray=[];
$("input:checkbox:checked").each(function () {
myarray.push($(this).attr('category_uid'));
});
Something like
var checked_cats = new Array();
$("input:checkbox:checked").each(function() {
checked_cats.push($(this).attr('category_uid'));
});
(not tested)
p.s. saw your tweet.
new Array() rather than the more reliable, and more concise, []. ;-)
[] has been correct array literal syntax for donkey's years (like, before JavaScript was handed to the ECMA; eons ago in computing terms). It works on IE6. Fortunately, I don't have (or need) access to earlier versions than that.push is supported in IE since version 5.5. Even on that version, I haven't found any evidence about the bug you talked about.Here's a more "pluginy" way to do this:
(function($){
$.fn.getAttributes = function(attribute){
var result = [];
$(this).each(function(){
var a = $(this).attr(attribute);
if(a)
result.push(a);
});
return result;
}
})(jQuery);
and then use it as follows :
var result = $("input:checkbox:checked").getAttributes("category_uid");
Haven't tested it, but it should work just fine.
$(), to attr()). Bad enough in application code, but plugin code should strive for efficiency. (Also, you forgot to declare your $ argument, but good form [intending to] use one.)
.map()) when jQuery already has such a method?
.attr()will only return the attribute value for the first element in the set.