I have several INPUTs:
<input type="text" name="entry[1]" value="aaa" id="firstEntry" />
<input type="text" name="entry[2]" value="bbb" id="secondEntry" />
<input type="text" name="entry[3]" value="ccc" id="thirdEntry" />
How to get "2" when I know that element id is "secondEntry"?
var name = $("#secondEntry").attr('name'); // name = "entry[2]"
But how to get the index 2 ? I need to know just index (2), not whole name (entry[2]).
Well the name is just a string, and you'd have to do the rest with string manipulation:
var name = $("#secondEntry").attr('name'); // name = "entry[2]"
name = name.substring(name.indexOf('[')+1); // name = "2]"
// if you want an integer
name = parseInt(name, 10); // name = 2
// if you want a string representation
name = name.substring(0, name.indexOf(']')); // name = "2"
If it is always in that format, ie entry[x], then you could use regular expressions;
var elename = $("#secondEntry").attr('name');
var i = elename.match("entry\\[([0-9])+\\]");
var ind = i[1];
var ind = parseInt(i[1]). But drop "entry" from the regex so it's not fragile (doesn't break on name changes).var re = /entry\[(\d{1})\]/;
var index = re.exec(string);
You can do the trick using regular expressions.
var name = $("#secondEntry").attr('name');
var index = name.substring( 6, name.length - 1 );
entry to item at some point, or if there are more than nine, or...
'entry[12413525]'.substring( 6, 'entry[12413525]'.length - 1 ) gives me "12413525".