Simone0是一位数吗？0为什么不是一位数？最小的一位数
的有关信息介绍如下：
位数是指一个整数所占有数位的个数。把占有一个数位的数叫一位数，占有两个数位的数叫两位数。看百度上所有的说法都认为1是最小的一位数。但我在某个英文网站上看到了一个不同的说法，该网站上明确指出0 is one digits。希望有关于0是以为数吗？0是几位数？类似的问题我也很希望能得到完备的解释。
首先，介绍了十进制数的概念。
sign ::= ’+’ | ’-’
digit ::= ’0’ | ’1’ | ’2’ | ’3’ | ’4’ | ’5’ | ’6’ | ’7’ | ’8’ | ’9’
这里digit指的是10个阿拉伯数字
indicator ::= ’e’ | ’E’
digits ::= digit [digit]...
这里定义了digits的概念，就是几位数
decimal-part ::= digits ’.’ [digits] | [’.’] digits
exponent-part ::= indicator [sign] digits
infinity ::= ’Infinity’ | ’Inf’
nan ::= ’NaN’ [digits] | ’sNaN’ [digits]
numeric-value ::= decimal-part [exponent-part] | infinity
numeric-string ::= [sign] numeric-value | [sign] nan
where the characters in the strings accepted for infinity and nan may be in any case.
decNumber module这个函数计算数的结构，这里给出了一个计算某个数值是几位数的例子，分别是-1234.50，0和数字负无穷大。
Examples:If DECDPUN were 4,如果这个数是-1234.50the value -1234.50 would be encoded with:digits = 6exponent = -2bits = 0x80lsu = {3450, 12}数0的各个参数的值为，这里很明确的指出数0的digits（几位数）是1，the value 0 would be:digits = 1exponent = 0bits = 0x00lsu = {0}–¥ (minus infinity) would be:digits = 1exponent = 0bits = 0xC0lsu = {0}
If DECDPUN were 4,如果这个数是-1234.50the value -1234.50 would be encoded with:digits = 6exponent = -2bits = 0x80lsu = {3450, 12}数0的各个参数的值为，这里很明确的指出数0的digits（几位数）是1，the value 0 would be:digits = 1exponent = 0bits = 0x00lsu = {0}–¥ (minus infinity) would be:digits = 1exponent = 0bits = 0xC0lsu = {0}
If DECDPUN were 4,如果这个数是-1234.50the value -1234.50 would be encoded with:digits = 6exponent = -2bits = 0x80lsu = {3450, 12}数0的各个参数的值为，这里很明确的指出数0的digits（几位数）是1，the value 0 would be:digits = 1exponent = 0bits = 0x00lsu = {0}–¥ (minus infinity) would be:digits = 1exponent = 0bits = 0xC0lsu = {0}
如果这个数是-1234.50the value -1234.50 would be encoded with:digits = 6exponent = -2bits = 0x80lsu = {3450, 12}数0的各个参数的值为，这里很明确的指出数0的digits（几位数）是1，the value 0 would be:digits = 1exponent = 0bits = 0x00lsu = {0}–¥ (minus infinity) would be:digits = 1exponent = 0bits = 0xC0lsu = {0}
the value -1234.50 would be encoded with:digits = 6exponent = -2bits = 0x80lsu = {3450, 12}数0的各个参数的值为，这里很明确的指出数0的digits（几位数）是1，the value 0 would be:digits = 1exponent = 0bits = 0x00lsu = {0}–¥ (minus infinity) would be:digits = 1exponent = 0bits = 0xC0lsu = {0}
digits = 6
exponent = -2
bits = 0x80
lsu = {3450, 12}
数0的各个参数的值为，这里很明确的指出数0的digits（几位数）是1，
the value 0 would be:
digits = 1
exponent = 0
bits = 0x00
lsu = {0}
–¥ (minus infinity) would be:
digits = 1
exponent = 0
bits = 0xC0
lsu = {0}
到这里，希望认为0不是一位数的人能意识到，可以认为0是一位数，而且认为0是一位数不是没有道理。
