Combining hover functions

Question

I have many <spans>s which need to group to change opacity after hover. All of them need to have unique IDs. Is there a way to combine all these hover functions to one function?

jQuery

//09 
 $('#c_09_241a, #c_09_241b, #c_09_241c, #c_09_241d').hover(
 function() {
 $('#c_09_241a, #c_09_241b, #c_09_241c, #c_09_241d').stop(true, true).css('opacity','1');
 },
 function() {
 $('#c_09_241a, #c_09_241b, #c_09_241c, #c_09_241d').stop(true, true).css('opacity','0');
 }); 
 $('#c_09_242a, #c_09_242b').hover(
 function() {
 $('#c_09_242a, #c_09_242b').stop(true, true).css('opacity','1');
 },
 function() {
 $('#c_09_242a, #c_09_242b').stop(true, true).css('opacity','0');
 });
 $('#c_09_245a, #c_09_245b').hover(
 function() {
 $('#c_09_245a, #c_09_245b').stop(true, true).css('opacity','1');
 },
 function() {
 $('#c_09_245a, #c_09_245b').stop(true, true).css('opacity','0');
 });
 $('#c_09_246a, #c_09_246b').hover(
 function() {
 $('#c_09_246a, #c_09_246b').stop(true, true).css('opacity','1');
 },
 function() {
 $('#c_09_246a, #c_09_246b').stop(true, true).css('opacity','0');
 });
 //08 
 $('#c_08_235a, #c_08_235b, #c_08_235c, #c_08_235d').hover(
 function() {
 $('#c_08_235a, #c_08_235b, #c_08_235c, #c_08_235d').stop(true, true).css('opacity','1');
 },
 function() {
 $('#c_08_235a, #c_08_235b, #c_08_235c, #c_08_235d').stop(true, true).css('opacity','0');
 }); 
 $('#c_08_236a, #c_08_236b').hover(
 function() {
 $('#c_08_236a, #c_08_236b').stop(true, true).css('opacity','1');
 },
 function() {
 $('#c_08_236a, #c_08_236b').stop(true, true).css('opacity','0');
 });
 $('#c_08_239a, #c_08_239b').hover(
 function() {
 $('#c_08_239a, #c_08_239b').stop(true, true).css('opacity','1');
 },
 function() {
 $('#c_08_239a, #c_08_239b').stop(true, true).css('opacity','0');
 });
 $('#c_08_240a, #c_08_240b').hover(
 function() {
 $('#c_08_240a, #c_08_240b').stop(true, true).css('opacity','1');
 },
 function() {
 $('#c_08_240a, #c_08_240b').stop(true, true).css('opacity','0');
 });
 //07 
 $('#c_07_227a, #c_07_227b').hover(
 function() {
 $('#c_07_227a, #c_07_227b').stop(true, true).css('opacity','1');
 },
 function() {
 $('#c_07_227a, #c_07_227b').stop(true, true).css('opacity','0');
 });
 $('#c_07_228a, #c_07_228b, #c_07_228c').hover(
 function() {
 $('#c_07_228a, #c_07_228b, #c_07_228c').stop(true, true).css('opacity','1');
 },
 function() {
 $('#c_07_228a, #c_07_228b, #c_07_228c').stop(true, true).css('opacity','0');
 });
 $('#c_07_007a, #c_07_007b').hover(
 function() {
 $('#c_07_007a, #c_07_007b').stop(true, true).css('opacity','1');
 },
 function() {
 $('#c_07_007a, #c_07_007b').stop(true, true).css('opacity','0');
 });
 $('#c_07_008a, #c_07_008b').hover(
 function() {
 $('#c_07_008a, #c_07_008b').stop(true, true).css('opacity','1');
 },
 function() {
 $('#c_07_008a, #c_07_008b').stop(true, true).css('opacity','0');
 });

HTML

<div id="rzuty09p" class="rzuty">
 <span id="c_09_241a" class="mieszkanie" title=""></span>
 <span id="c_09_241b" class="mieszkanie" title=""></span>
 <span id="c_09_241c" class="mieszkanie" title=""></span>
 <span id="c_09_241d" class="mieszkanie" title=""></span>
 <span id="c_09_242a" class="mieszkanie" title=""></span>
 <span id="c_09_242b" class="mieszkanie" title=""></span>
 <span id="c_09_243" class="mieszkanie" title=""></span>
 <span id="c_09_244" class="mieszkanie" title=""></span>
 <span id="c_09_245a" class="mieszkanie" title=""></span>
 <span id="c_09_245b" class="mieszkanie" title=""></span>
 <span id="c_09_246a" class="mieszkanie nie" title=""></span>
 <span id="c_09_246b" class="mieszkanie nie" title=""></span>
 </div> 
<div id="rzuty08p" class="rzuty">
 <span id="c_08_235a" class="mieszkanie" title=""></span>
 <span id="c_08_235b" class="mieszkanie" title=""></span>
 <span id="c_08_235c" class="mieszkanie" title=""></span>
 <span id="c_08_235d" class="mieszkanie" title=""></span>
 <span id="c_08_236a" class="mieszkanie nie" title=""></span>
 <span id="c_08_236b" class="mieszkanie nie" title=""></span>
 <span id="c_08_237" class="mieszkanie" title=""></span>
 <span id="c_08_238" class="mieszkanie" title=""></span>
 <span id="c_08_239a" class="mieszkanie" title=""></span>
 <span id="c_08_239b" class="mieszkanie" title=""></span>
 <span id="c_08_240a" class="mieszkanie" title=""></span>
 <span id="c_08_240b" class="mieszkanie" title=""></span>
 </div> 
<div id="rzuty07p" class="rzuty">
 <span id="c_07_226" class="mieszkanie" title=""></span>
 <span id="c_07_227a" class="mieszkanie" title=""></span>
 <span id="c_07_227b" class="mieszkanie" title=""></span>
 <span id="c_07_228a" class="mieszkanie" title=""></span>
 <span id="c_07_228b" class="mieszkanie" title=""></span>
 <span id="c_07_228c" class="mieszkanie" title=""></span>
 <span id="c_07_229" class="mieszkanie nie" title=""></span>
 <span id="c_07_005" class="mieszkanie" title=""></span>
 <span id="c_07_006" class="mieszkanie" title=""></span>
 <span id="c_07_007a" class="mieszkanie nie" title=""></span>
 <span id="c_07_007b" class="mieszkanie nie" title=""></span>
 <span id="c_07_008a" class="mieszkanie" title=""></span>
 <span id="c_07_008b" class="mieszkanie" title=""></span>
 </div>

Answer 1

var groups = [
 '09_241', '09_242', '09_245', '09_246',
 '08_235', '08_236', '08_239', '08_240',
 '07_227', '07_228', '07_007', '07_008'
];
$.each(groups, function(i, group) {
 var $group = $('[id^=c_' + group + ']');
 $group.hover(function() {
 $group.stop(true, true).css('opacity', '1');
 }, function() {
 $group.stop(true, true).css('opacity', '0');
 });
});

Here's the fiddle: http://jsfiddle.net/W8GA3/

This is similar to @Matt's solution, with the following key differences:

1. Sane Selectors - There's no need to add all those selectors by hand. Simply use an attribute selector to select all elements that start with a given string.
2. Selector caching - If there's one thing you can do to your code to keep it fast, it's selector caching.
3. $.each - We're using jQuery's each helper to loop through the array, since it also supports older browsers (forEach is not supported in IE < 9).

---

If you want to, you could even build that original groups array dynamically, which will make this much easier to maintain:

var groups = [];
$('[id^=c_]').each(function() {
 // Extract group number from ID
 var group = this.id.substring(2, 8);
 // If the ID is not in the groups array, add it
 ~$.inArray( group, groups ) || groups.push( group );
});

Here's the fiddle: http://jsfiddle.net/W8GA3/1/

• gidzior: this is super cool, new level for me, thx a lot
• Joseph Silber: @gidzior - Glad it helped you. You might have to modify some bits of the code depending on your naming conventions. $('[id^=c_]') and this.id.substring(2, 8) make a lot of assumptions, and I hope I wasn't too wrong...