function convert2Int(num) {
num = parseInt(num);
 return isNaN(num) ? 0 : num;
        }
$(function () {
                    var rows = $("#saleTable tr").length - 1;
             
       var columns = $("#saleTable tr td").length / rows;
//alert($("#saleTable tr:eq(2) td:eq(0)").html());
                    for (var j = 0; j < columns; j++) {
                
        var tempResult = 0;
                        for (var i = 1; i < 
rows; i++) {
                            //        alert($("#saleTable 
tr:eq(" + i + ") td:eq(" + j + ")").html());
                            
tempResult += convert2Int($("#saleTable tr:eq(" + i + ") td:eq(" + j + 
")").html());
                        }
                        
$("#saleTable tr:eq(" + rows + ") td:eq(" + j + ")").html(tempResult);
       
             }
                });
原文:http://www.cnblogs.com/kevin1988/p/3709453.html