How to get all elements which name starts with some string?
JavascriptHtmlJavascript Problem Overview
I have an HTML page. I would like to extract all elements whose name starts with "q1_".
How can I achieve this in JavaScript?
Javascript Solutions
Solution 1 - Javascript
A quick and easy way is to use jQuery and do this:
var $eles = $(":input[name^='q1_']").css("color","yellow");
That will grab all elements whose name attribute starts with 'q1_'. To convert the resulting collection of jQuery objects to a DOM collection, do this:
var DOMeles = $eles.get();
see http://api.jquery.com/attribute-starts-with-selector/
In pure DOM, you could use getElementsByTagName to grab all input elements, and loop through the resulting array. Elements with name starting with 'q1_' get pushed to another array:
var eles = [];
var inputs = document.getElementsByTagName("input");
for(var i = 0; i < inputs.length; i++) {
if(inputs[i].name.indexOf('q1_') == 0) {
eles.push(inputs[i]);
}
}
Solution 2 - Javascript
You can use getElementsByName("input") to get a collection of all the inputs on the page. Then loop through the collection, checking the name on the way. Something like this:
<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>JS Bin</title>
</head>
<body>
<input name="q1_a" type="text" value="1A"/>
<input name="q1_b" type="text" value="1B"/>
<input name="q1_c" type="text" value="1C"/>
<input name="q2_d" type="text" value="2D"/>
<script type="text/javascript">
var inputs = document.getElementsByTagName("input");
for (x = 0 ; x < inputs.length ; x++){
myname = inputs[x].getAttribute("name");
if(myname.indexOf("q1_")==0){
alert(myname);
// do more stuff here
}
}
</script>
</body>
</html>
Solution 3 - Javascript
HTML DOM querySelectorAll() method seems apt here.
W3School Link given here
Syntax (As given in W3School)
document.querySelectorAll(CSS selectors)
So the answer.
document.querySelectorAll("[name^=q1_]")
Edit:
Considering FLX's suggestion adding link to MDN here
Solution 4 - Javascript
Using pure java-script, here is a working code example
<input type="checkbox" name="fruit1" checked/>
<input type="checkbox" name="fruit2" checked />
<input type="checkbox" name="fruit3" checked />
<input type="checkbox" name="other1" checked />
<input type="checkbox" name="other2" checked />
<br>
<input type="button" name="check" value="count checked checkboxes name starts with fruit*" onClick="checkboxes();" />
<script>
function checkboxes()
{
var inputElems = document.getElementsByTagName("input"),
count = 0;
for (var i=0; i<inputElems.length; i++) {
if (inputElems[i].type == "checkbox" && inputElems[i].checked == true &&
inputElems[i].name.indexOf('fruit') == 0)
{
count++;
}
}
alert(count);
}
</script>
Solution 5 - Javascript
You can try using http://jquery.com/">jQuery</a> with the http://api.jquery.com/attribute-contains-prefix-selector/">Attribute Contains Prefix Selector.
$('[id|=q1_]')
Haven't tested it though.