Question

I working on something where I need two functions.

1 – I need to look at a group of children under the same parent and based on a class name, “active”, add that element’s ID to an array.

['foo-a','foo-b','foo-d']

2 – I then iterate through all the children in another parent and for each element I want to find out if it has any class name that match the ids in the array.

Does this element have class foo-a, foo-b or foo-d?

Answer 1

var active = $("#foo").find(".active").map(function() {
    return this.id;
}).get();

$("#anotherParent *").each(function() {
   var that = this;
   var classes = $(this).attr("class");
   if(classes.indexOf(" ") !== -1) {
       classes = classes.split(" ");
   } else {
       classes = [ classes ];  
   }
   $.each(classes, function(i, val) {
       if($.inArray(val, active)) {

           // this element has one of 'em, do something with it
           $(that).hide();
       }
   });
});