js保留位和取整

 //hold是保留位，例，元，角，分
 //integerType是在保留位的基础上，如果后面有值，向上向下取整
 calAmount:function(hold,integerType,amount){
         if(hold=='YUAN'){
           if(integerType=='ROUND'){
             //四舍五入
             return amount.toFixed(0);
           }else if(integerType=='LASTINTERCEPT'){
             //舍0（去掉保留位后面的数字）
             return parseInt(amount);
           }else if(integerType=='CARRYOVER'){
             //进位
             return Math.ceil(amount);
           }
         }else if(hold=='JIAO'){
           if(integerType=='ROUND'){
             //四舍五入
             return amount.toFixed(1);
           }else if(integerType=='LASTINTERCEPT'){
             //舍0
             var am = amount.toString();
             var nu = am.indexOf('.');
             if(am.length-nu>2){
               var am1 = amount.toFixed(2).toString();
               return am1.substring(0,am1.length-1);
             }
             return amount;
           }else if(integerType=='CARRYOVER'){
             //进位
             var am = amount.toString();
             var nu = am.indexOf('.');
             if(am.length-nu>2){
               var am1 = (amount+0.1).toFixed(2).toString();
               return am1.substring(0,am1.length-1);
             }
             return amount;
           }
         }else if(hold=='FEN'){
           if(integerType=='ROUND'){
             //四舍五入
             return amount.toFixed(2);
           }else if(integerType=='LASTINTERCEPT'){
             //舍0
             var am = amount.toString();
             var nu = am.indexOf('.');
             if(am.length-nu>3){
               var am1 = amount.toFixed(3).toString();
               return am1.substring(0,am1.length-1);
             }
             return amount;
           }else if(integerType=='CARRYOVER'){
             //进位
             var am = amount.toString();
             var nu = am.indexOf('.');
             if(am.length-nu>3){
               var am1 = (amount+0.01).toFixed(3).toString();
               return am1.substring(0,am1.length-1);
             }
             return amount;
           }
         }
       }