正则表达式仅验证 0-9 的数字，最多 8 位数字直到一个点，最多只有两位小数

Question

I haven't used regular expressions at all, so I'm having difficulty troubleshooting. I'm looking for a regex that can help me to validate if there are only digits from 0-9, only 8 digits till a dot and two decimals as maximum.

For example:

33445566.09

/[0-9]/

Answer 1

/[0-9]{1,8}\.[0-9]{1,2}/

If you want to just match or not

[0-9] means match 0 or 1 or... 9

{1,8} means it can match minimum 1 and maximum 8

\. means escape.

If you want to get the group just use () in the regex

/([0-9]{1,8})\.([0-9]{1,2})/

This way you can get 33445566 and 09

Answer 2

Try this:

    String input = "123456789.12";
    Pattern pattern = Pattern.compile("^[0-9]{1,8}\\.[0-9]{1,2}$");
    Matcher matcher = pattern.matcher(input);
    System.out.println(matcher.matches()); //false

• ^ start of line
• $ end of line
• [0-9] only 0123456789
• {1,8} symbols count from 1 to 8 include

Answer 3

I think you need

\d{1,8}(.\d{1,2})?