Some handy feature in jQuery

        <span xmlns=''><p><span style='font-family:Times New Roman; font-size:13pt'><strong>attr( key, fn )
        </strong></span></p><p><span style='font-family:Times New Roman; font-size:12pt'>Sets title attribute from src attribute.
        </span></p><p><span style='font-family:Courier New; font-size:10pt'> $("img").attr("title", function() { return this.src });
        </span></p><p>
         </p><p><span style='font-family:Times New Roman; font-size:13pt'><strong>toggleClass( class )
        </strong></span></p><p><code>$("p").toggleClass("selected")
        </pre></p><p>
         </p><p>Before
        </p><p><code><p>Hello</p><p class="selected">Hello Again</p>
        </pre></p><p>
         </p><p>After
        </p><p><code>[ <p class="selected">Hello</p>, <p>Hello Again</p> ]
        </pre></p><p>
         </p><p>
         </p><p><span style='font-family:Times New Roman; font-size:18pt'><strong>get()
        </strong></span></p><p>return an array that contains in jQuery object
        </p><p>
         </p><p><span style='font-family:Times New Roman; font-size:18pt'><strong>get( num )
        </strong></span></p><p>return an
        </p><p>
         </p><p><span style='font-family:Times New Roman; font-size:18pt'><strong>html(), text()  and val()
        </strong></span></p><p><span style='font-family:Times New Roman; font-size:18pt'><strong>html(val), text(val) and val(val)
        </strong></span></p><p><span style='font-family:Times New Roman; font-size:18pt'><strong>end()
        </strong></span></p><p><span style='font-family:Times New Roman; font-size:12pt'>Revert the most recent 'destructive' operation, changing the set of matched elements to its previous state (right before the destructive operation).
        </span></p><p><span style='font-family:Times New Roman; font-size:12pt'>If there was no destructive operation before, an empty set is returned.
        </span></p><p><span style='font-family:Times New Roman; font-size:12pt'>A 'destructive' operation is any operation that changes the set of matched jQuery elements. These functions are: </span><span style='font-family:Courier New; font-size:10pt'>add</span><span style='font-family:Times New Roman; font-size:12pt'>, </span><span style='font-family:Courier New; font-size:10pt'>children</span><span style='font-family:Times New Roman; font-size:12pt'>, </span><span style='font-family:Courier New; font-size:10pt'>clone</span><span style='font-family:Times New Roman; font-size:12pt'>, </span><span style='font-family:Courier New; font-size:10pt'>filter</span><span style='font-family:Times New Roman; font-size:12pt'>, </span><span style='font-family:Courier New; font-size:10pt'>find</span><span style='font-family:Times New Roman; font-size:12pt'>, </span><span style='font-family:Courier New; font-size:10pt'>not</span><span style='font-family:Times New Roman; font-size:12pt'>, </span><span style='font-family:Courier New; font-size:10pt'>next</span><span style='font-family:Times New Roman; font-size:12pt'>, </span><span style='font-family:Courier New; font-size:10pt'>parent</span><span style='font-family:Times New Roman; font-size:12pt'>, </span><span style='font-family:Courier New; font-size:10pt'>parents</span><span style='font-family:Times New Roman; font-size:12pt'>, </span><span style='font-family:Courier New; font-size:10pt'>prev</span><span style='font-family:Times New Roman; font-size:12pt'> and </span><span style='font-family:Courier New; font-size:10pt'>siblings</span><span style='font-family:Times New Roman; font-size:12pt'>.
        </span></p></span>