+
+ // Determine the position of an element within
+ // the matched set of elements
+ index: function( elem ) {
+ if ( !elem || typeof elem === "string" ) {
+ return jQuery.inArray( this[0],
+ // If it receives a string, the selector is used
+ // If it receives nothing, the siblings are used
+ elem ? jQuery( elem ) : this.parent().children() );
+ }
+ // Locate the position of the desired element
+ return jQuery.inArray(
+ // If it receives a jQuery object, the first element is used
+ elem.jquery ? elem[0] : elem, this );
+ },