JavaScript正则表达式尾随零

Question

Javascript regex

I have following regex, i want to un-match zeros after decimal, 1.0 or 1.00 should not match but should match 1.25 or 1.2

^(?!0\.)(?:\d{1,3}(?:,\d{3})+|\d+)(?:\.\d{1,2})?$

it accepts following inputs

1.00
1.25
does not accept leading zero ex. 0.25
100
1000
1,000
100,000

Answer 1

You need to add a negative lookahead at the end:

^(?!0\.)(?:\d{1,3}(?:,\d{3})+|\d+)(?:\.(?!0+$)\d{1,2})?$
                                       ^^^^^^^

See the regex demo

The (?!0+$) negative lookahead restricts the subsequent consuming subpattern \\d{1,2})?$ so that the \\d{1,2} cannot match 00 or 0 any longer.

Answer 2

这是从相反的角度看待它是允许的，而不是排除的：

^[1-9],?[0-9]*.?[1-9]*$