這是對表格進行排序的一個jquery，誰能解釋一下這個函數頭啊？如下：{ var $sortOrder = 0; //排序類型 1表示升序，0表示降序var $table = $('table#shop');$('th', $table).each(function( column ){//處理三種有可能存在的排序字段，比較方法var findSortKey;if( $(this).is('.sort-title') || $(this).is('.sort-author') ){findSortKey = function( $cell ){return $cell.find('.sort-title').text().toUpperCase()+ '' +$cell.text().toUpperCase();}}else if( $(this).is('.sort-date') ){findSortKey = function( $cell ){return Date.parse('1' + $cell.text());}}else if( $(this).is('.sort-price') ){findSortKey = function( $cell ){var key = parseFloat($cell.text().replace(/^[^\d.]*/, ''))return isNaN(key) ? 0 : key;}}//排序if( findSortKey ){$(this).addClass('clickable').hover(function(){$(this).addClass('hover');var $title = $sortOrder == 0 ? '升序' : '降序';$(this).attr('title', '按'+ $(this).html() + $title +'排列');}, function(){$(this).removeClass('hover');}).click(function(){$sortOrder = $sortOrder == 0 ? 1 : 0;var rows = $table.find('tbody > tr').get();$.each( rows, function( index, row ){row.sortKey = findSortKey($(row).children('td').eq(column));});//排序方法rows.sort(function( a, b ){if( $sortOrder == 1 ){//升序if(a.sortKey < b.sortKey) return -1;if(a.sortKey > b.sortKey) return 1; return 0;}else{//降序if(a.sortKey < b.sortKey) return 1;if(a.sortKey > b.sortKey) return -1; return 0;} });//排序后的對象添加給$table$.each( rows, function( index, row ){$table.children('tbody').append(row);row.sortKey = null;});$table.find('td').removeClass('sorted').filter(':nth-child('+ (column + 1) +')').addClass('sorted');//重新賦予奇偶行的樣式$table.alterRowColors();});} }); });