Question

How does this data.target == this work?

jquery example

.mouseup(function(data, handler)
        {
           if(data.target == this)
           {
              // some code
           }
        })

Does this compare the objects by comparing each of their respective properties?

I need this check because I want the mouseup only on the parent div and on one child.

if (data.target == this || * if this has className XXX  * ) {
   // some code
}

Answer 1

if (data.target == this) evaluates to true if this refers to the same object in memory as data.target.

The == operator does not compare member values. See Object comparison in JavaScript.