是否有正则表达式匹配最多7位数的浮点数？

Question

我正在寻找一个正则表达式来匹配最多7位数的浮点数.我无法弄清楚如何处理小数点.甚至可以将它与正则表达式相匹配吗？小数点左边必须至少有1位数字,右边有0-6位数字,但总位数必须是7或更少.

例子:

好:

• 1.234567
• 0.1
• 1234567
• 1

坏:

• 0.1234567
• 12345678
• 1.2.34567

Answer 1

以下应该有效:

^(?!.*\..*\.|\d{8})\d[\d.]{,7}$

示例:http://www.rubular.com/r/gglVngm0pH

说明:

^            # beginning of string anchor
(?!          # start negative lookahead (fail if following regex can match)
   .*\..*\.    # two or more '.' characters exist in the string
   |           # OR
   \d{8}       # eight consecutive digits in the string
)            # end negative lookahead
\d           # match a digit
[\d.]{,7}    # match between 0 and 7 characters that are either '.' or a digit
$            # end of string anchor