How do I write this JQuery function in plain JavaScript?

Question

can you please help me to write this function in plain JavaScript in the most efficient way.

//Selects all elements matched by <input> that have a name value 
//exactly equal to myname.
$("input[@name=myname]")

There isn't really an "efficient" way to do this in Javascript other than using the exact same method jQuery is using. jQuery has done a lot of work on making these selectors extremely efficient. Is there a reason you can't use jQuery, or is this just an academic exercise? — Codeman
– Codeman, Commented Jan 12, 2013 at 0:54
No it's not an academic exercise, I'm using JavaScript in my program, and to evaluate JQuery every time I load the page is not good at all.. — Vor
– Vor, Commented Jan 12, 2013 at 0:57
Ok? But a lot of existing web sites do that - successfully ;) Even stackoverflow. — lethal-guitar
– lethal-guitar, Commented Jan 12, 2013 at 0:57
Most (read:every) modern browser caches javascript, so it will not "load" jQuery every time you load the page. — Codeman
– Codeman, Commented Jan 12, 2013 at 0:58
Especially if you load it from google, like many sites do. Just look at the source of stackoverflow. Think about it, who doesn't have Google in his or her browser's cache - maybe 0.2% of the whole internet? — lethal-guitar
– lethal-guitar, Commented Jan 12, 2013 at 1:01

VisioN · Accepted Answer · 2013-01-12 00:55:27Z

5

var els = document.getElementsByTagName("input"),
    arr = [];

for (var i = 0, l = els.length; i < l; i++) {
    if (els.name === "myname") {
        arr.push(els);
    }
}

console.log(arr);

Or for modern browsers:

var arr = document.querySelectorAll("input[name='myname']");
console.log(arr);

answered Jan 12, 2013 at 0:55

VisioN

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3 Comments

Vor Over a year ago

Great thank you very much! the second approach looks very nice and clean

VisioN Over a year ago

@Vor However it is not supported by IE < 8.

Vor Over a year ago

That's fine, as long as webkit support it =)

97ldave · Accepted Answer · 2013-01-12 00:58:25Z

4

Is this what you are looking for:

document.getElementsByName("myname");

answered Jan 12, 2013 at 0:58

97ldave

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1 Comment

Vor Over a year ago

No, it's not, It's just an example, I wouldn't use 'name' in real program

Diego · Accepted Answer · 2013-01-12 01:00:02Z

3

Assuming each element in the form has a unique name, this method is the fastest:

var element = document.MyForm.getElementsByName('myname')[0];

document.querySelectorAll() may be faster if name is shared by elements of different tags, but support is limited .

edited Jan 12, 2013 at 1:00

answered Jan 12, 2013 at 0:56

Diego

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1 Comment

Vor Over a year ago

Sorry, If my question is not clear enough, but 'name' was just an example

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