匹配字符串中最后一个数字的正则表达式 [英] Regular expression to match last number in a string

问题描述

我需要提取字符串中的最后一个数字.我正在尝试使用正则表达式和负前瞻来做到这一点，但它不起作用.这是我拥有的正则表达式:

I need to extract the last number that is inside a string. I'm trying to do this with regex and negative lookaheads, but it's not working. This is the regex that I have:

\d+(?!\d+)

这些是一些字符串，只是为了给你一个想法，以及正则表达式应该匹配什么:

And these are some strings, just to give you an idea, and what the regex should match:

ARRAY[123]         matches 123 
ARRAY[123].ITEM[4] matches 4
B:1000             matches 1000
B:1000.10          matches 10

等等.正则表达式匹配数字，但全部匹配.我不明白为什么负面前瞻不起作用.有人愿意解释吗?

And so on. The regex matches the numbers, but all of them. I don't get why the negative lookahead is not working. Any one care to explain?

推荐答案

你的正则表达式 \d+(?!\d+) 说

Your regex \d+(?!\d+) says

匹配任何没有紧随其后的数字.

match any number if it is not immediately followed by a number.

这是不正确的.如果一个数字后面没有(跟在任何地方，而不是立即)任何其他数字，则该数字在最后.

which is incorrect. A number is last if it is not followed (following it anywhere, not just immediately) by any other number.

当翻译成正则表达式时，我们有:

When translated to regex we have:

(\d+)(?!.*\d)

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