用千位分隔符装饰字符串中的数字

Question

A have a string that contains one ore more number. The numbers are normally integers, but also decimal could be expected at some point. I looking for a solution that adds the thousand separator(. or ,) to all numbers inside the string.

For example

1. 100000 -> ?100,000?
2. ?100000?50000 -> ?100,000?50,000
3. X10000.5? -> X100,00.5?

Any idea?

Answer 1

A hacky solution in pure regex is to replace all occurences of

(?<=\d)(\d{3})(?!\d)

with ,$1 . This is, of course, very limited, as it only adds one separator per number, and also adds separators after a comma. See regex101 demo.

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A far cleaner solution is to search for numbers using a regex such as \\d+(?:\\.\\d+)? , convert each match to a number, and re-insert the formatted number into the text.

(You'll have to forgive me for not including any code, but I haven't coded in C# in ages.)