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;
          }
        }
      }