正则表达式要求一个正数值（5,2）禁止前导零

Question

正则表达式模式是否可以对数值强制执行以下约束组合？

     the number must be >= 1 and <= 999 
     (decimal point cannot be the first character in the string?)

     the number can be an integer or a number with a fractional component

     when it has a fractional component, 
     no more than 2 digits to the right of the decimal point 
     EDIT: but at least one digit to the right

     must not have leading zero(s)

Answer 1

Perl语法：

^+?(?:(?:999(?:\.0{1,2})?)|(?:(?!999)[1-9]\d{0,2}(?:\.\d{1,2})?))$

Answer 2

是..

^(?!999[.](0*[1-9]+$))(?!0|[.])\d{1,3}([.]\d{1,2})?$

Answer 3

我会选择这个：

/^
(?:
  999.0*                      # 999.000
  |                           # or
  [1-9]\d{,2}((?<!999)\.\d+)? # 1-998 plus optional .\d*
)
$/x