Round & FormatNumber 四捨五入的区别

VBScript Round() 四捨五入函数，但是使用 Round() 四捨五入为近偶取整，平时多数是以大于等于 5 的数值进位、小于 5 的数值捨去。FormatNumber() 的值比较符合平常用的值。使用 Round() 近偶取整则于偶数才进位与 FormatNumber() 四捨五入有差异由下表来分析差异点。这种方式可以减少四捨五入误差的累积，但也可能造成一些不符合预期的结果，所产生的误差。

运算的数值	Round()	FormatNumber()	差异处
0.1	Round(0.1, 0) = 0	FormatNumber(0.1, 0) = 0	-
0.2	Round(0.2, 0) = 0	FormatNumber(0.2, 0) = 0	-
0.3	Round(0.3, 0) = 0	FormatNumber(0.3, 0) = 0	-
0.4	Round(0.4, 0) = 0	FormatNumber(0.4, 0) = 0	-
0.5	Round(0.5, 0) = 0	FormatNumber(0.5, 0) = 1	差异处
0.6	Round(0.6, 0) = 1	FormatNumber(0.6, 0) = 1	-
0.7	Round(0.7, 0) = 1	FormatNumber(0.7, 0) = 1	-
0.8	Round(0.8, 0) = 1	FormatNumber(0.8, 0) = 1	-
0.9	Round(0.9, 0) = 1	FormatNumber(0.9, 0) = 1	-
1.0	Round(1.0, 0) = 1	FormatNumber(1.0, 0) = 1	-
1.1	Round(1.1, 0) = 1	FormatNumber(1.1, 0) = 1	-
1.2	Round(1.2, 0) = 1	FormatNumber(1.2, 0) = 1	-
1.3	Round(1.3, 0) = 1	FormatNumber(1.3, 0) = 1	-
1.4	Round(1.4, 0) = 1	FormatNumber(1.4, 0) = 1	-
1.5	Round(1.5, 0) = 2	FormatNumber(1.5, 0) = 2	-
1.6	Round(1.6, 0) = 2	FormatNumber(1.6, 0) = 2	-
1.7	Round(1.7, 0) = 2	FormatNumber(1.7, 0) = 2	-
1.8	Round(1.8, 0) = 2	FormatNumber(1.8, 0) = 2	-
1.9	Round(1.9, 0) = 2	FormatNumber(1.9, 0) = 2	-
2.0	Round(2.0, 0) = 2	FormatNumber(2.0, 0) = 2	-
2.1	Round(2.1, 0) = 2	FormatNumber(2.1, 0) = 2	-
2.2	Round(2.2, 0) = 2	FormatNumber(2.2, 0) = 2	-
2.3	Round(2.3, 0) = 2	FormatNumber(2.3, 0) = 2	-
2.4	Round(2.4, 0) = 2	FormatNumber(2.4, 0) = 2	-
2.5	Round(2.5, 0) = 2	FormatNumber(2.5, 0) = 3	差异处
2.6	Round(2.6, 0) = 3	FormatNumber(2.6, 0) = 3	-
2.7	Round(2.7, 0) = 3	FormatNumber(2.7, 0) = 3	-
2.8	Round(2.8, 0) = 3	FormatNumber(2.8, 0) = 3	-
2.9	Round(2.9, 0) = 3	FormatNumber(2.9, 0) = 3	-
3.0	Round(3.0, 0) = 3	FormatNumber(3.0, 0) = 3	-
3.1	Round(3.1, 0) = 3	FormatNumber(3.1, 0) = 3	-
3.2	Round(3.2, 0) = 3	FormatNumber(3.2, 0) = 3	-
3.3	Round(3.3, 0) = 3	FormatNumber(3.3, 0) = 3	-
3.4	Round(3.4, 0) = 3	FormatNumber(3.4, 0) = 3	-
3.5	Round(3.5, 0) = 4	FormatNumber(3.5, 0) = 4	-
3.6	Round(3.6, 0) = 4	FormatNumber(3.6, 0) = 4	-
3.7	Round(3.7, 0) = 4	FormatNumber(3.7, 0) = 4	-
3.8	Round(3.8, 0) = 4	FormatNumber(3.8, 0) = 4	-
3.9	Round(3.9, 0) = 4	FormatNumber(3.9, 0) = 4	-
4.0	Round(4.0, 0) = 4	FormatNumber(4.0, 0) = 4	-
4.1	Round(4.1, 0) = 4	FormatNumber(4.1, 0) = 4	-
4.2	Round(4.2, 0) = 4	FormatNumber(4.2, 0) = 4	-
4.3	Round(4.3, 0) = 4	FormatNumber(4.3, 0) = 4	-
4.4	Round(4.4, 0) = 4	FormatNumber(4.4, 0) = 4	-
4.5	Round(4.5, 0) = 4	FormatNumber(4.5, 0) = 5	差异处
4.6	Round(4.6, 0) = 5	FormatNumber(4.6, 0) = 5	-
4.7	Round(4.7, 0) = 5	FormatNumber(4.7, 0) = 5	-
4.8	Round(4.8, 0) = 5	FormatNumber(4.8, 0) = 5	-
4.9	Round(4.9, 0) = 5	FormatNumber(4.9, 0) = 5	-
5.0	Round(5.0, 0) = 5	FormatNumber(5.0, 0) = 5	-
5.1	Round(5.1, 0) = 5	FormatNumber(5.1, 0) = 5	-
5.2	Round(5.2, 0) = 5	FormatNumber(5.2, 0) = 5	-
5.3	Round(5.3, 0) = 5	FormatNumber(5.3, 0) = 5	-
5.4	Round(5.4, 0) = 5	FormatNumber(5.4, 0) = 5	-
5.5	Round(5.5, 0) = 6	FormatNumber(5.5, 0) = 6	-
5.6	Round(5.6, 0) = 6	FormatNumber(5.6, 0) = 6	-
5.7	Round(5.7, 0) = 6	FormatNumber(5.7, 0) = 6	-
5.8	Round(5.8, 0) = 6	FormatNumber(5.8, 0) = 6	-
5.9	Round(5.9, 0) = 6	FormatNumber(5.9, 0) = 6	-
6.0	Round(6.0, 0) = 6	FormatNumber(6.0, 0) = 6	-
6.1	Round(6.1, 0) = 6	FormatNumber(6.1, 0) = 6	-
6.2	Round(6.2, 0) = 6	FormatNumber(6.2, 0) = 6	-
6.3	Round(6.3, 0) = 6	FormatNumber(6.3, 0) = 6	-
6.4	Round(6.4, 0) = 6	FormatNumber(6.4, 0) = 6	-
6.5	Round(6.5, 0) = 6	FormatNumber(6.5, 0) = 7	差异处
6.6	Round(6.6, 0) = 7	FormatNumber(6.6, 0) = 7	-
6.7	Round(6.7, 0) = 7	FormatNumber(6.7, 0) = 7	-
6.8	Round(6.8, 0) = 7	FormatNumber(6.8, 0) = 7	-
6.9	Round(6.9, 0) = 7	FormatNumber(6.9, 0) = 7	-
7.0	Round(7.0, 0) = 7	FormatNumber(7.0, 0) = 7	-
7.1	Round(7.1, 0) = 7	FormatNumber(7.1, 0) = 7	-
7.2	Round(7.2, 0) = 7	FormatNumber(7.2, 0) = 7	-
7.3	Round(7.3, 0) = 7	FormatNumber(7.3, 0) = 7	-
7.4	Round(7.4, 0) = 7	FormatNumber(7.4, 0) = 7	-
7.5	Round(7.5, 0) = 8	FormatNumber(7.5, 0) = 8	-
7.6	Round(7.6, 0) = 8	FormatNumber(7.6, 0) = 8	-
7.7	Round(7.7, 0) = 8	FormatNumber(7.7, 0) = 8	-
7.8	Round(7.8, 0) = 8	FormatNumber(7.8, 0) = 8	-
7.9	Round(7.9, 0) = 8	FormatNumber(7.9, 0) = 8	-
8.0	Round(8.0, 0) = 8	FormatNumber(8.0, 0) = 8	-
8.1	Round(8.1, 0) = 8	FormatNumber(8.1, 0) = 8	-
8.2	Round(8.2, 0) = 8	FormatNumber(8.2, 0) = 8	-
8.3	Round(8.3, 0) = 8	FormatNumber(8.3, 0) = 8	-
8.4	Round(8.4, 0) = 8	FormatNumber(8.4, 0) = 8	-
8.5	Round(8.5, 0) = 8	FormatNumber(8.5, 0) = 9	差异处
8.6	Round(8.6, 0) = 9	FormatNumber(8.6, 0) = 9	-
8.7	Round(8.7, 0) = 9	FormatNumber(8.7, 0) = 9	-
8.8	Round(8.8, 0) = 9	FormatNumber(8.8, 0) = 9	-
8.9	Round(8.9, 0) = 9	FormatNumber(8.9, 0) = 9	-
9.0	Round(9.0, 0) = 9	FormatNumber(9.0, 0) = 9	-
9.1	Round(9.1, 0) = 9	FormatNumber(9.1, 0) = 9	-
9.2	Round(9.2, 0) = 9	FormatNumber(9.2, 0) = 9	-
9.3	Round(9.3, 0) = 9	FormatNumber(9.3, 0) = 9	-
9.4	Round(9.4, 0) = 9	FormatNumber(9.4, 0) = 9	-
9.5	Round(9.5, 0) = 10	FormatNumber(9.5, 0) = 10	-
9.6	Round(9.6, 0) = 10	FormatNumber(9.6, 0) = 10	-
9.7	Round(9.7, 0) = 10	FormatNumber(9.7, 0) = 10	-
9.8	Round(9.8, 0) = 10	FormatNumber(9.8, 0) = 10	-
9.9	Round(9.9, 0) = 10	FormatNumber(9.9, 0) = 10	-

Round() 及 FormatNumber() Rounding 主要差异处比较

FormatNumber() 函数

FormatNumber(2.5,0)

FormatNumber(4.5,0)

FormatNumber(6.5,0)

FormatNumber(8.5,0)

Round() 函数

Round(2.5)

Round(4.5)

Round(6.5)

Round(8.5)

Coding 时 ASP 四捨五入函数之使用则依照需求来选择 Round() 及 FormatNumber() 函数。

ASPX IEEEremainder

Math.IEEEremainder(Double, Double) 传回指定数字除以另一个指定数字所得的余数，根据 IEEE 754 二进位浮点数算术标准。使用 Math.IEEEremainder 可以避免舍入误差，并且保持与 IEEE 754 标准的一致性。例如在计算角度或周期性函数时，可以使用 Math.IEEEremainder 来将角度限制在一个范围内，而不会出现负数或超过 360 度的情况。IEEE 754 标准是定义浮点数表示和运算的国际标准。浮点数是用来近似表示实数的数值格式，它由符号位、指数位和有效数位组成。IEEE 754 标准规定了不同的浮点数格式，例如单精度、双精度和扩展精度，以及相关的运算规则，常使用于加法、减法、乘法、除法和取余数。IEEE 754 标准还定义特殊的浮点数值，例如无穷大、非数和捨入模式。IEEE 754 标准的目的是为了提供一种可移植和可靠的浮点数计算方法，并且能够处理各种异常情况。