Who can help me with defining a regular expression?

Question

Henk-Jan Ramaker 2016-9-8

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/302396-who-can-help-me-with-defining-a-regular-expression

关闭： MATLAB Answer Bot 2021-8-20

I have lines of text that might look like this:

@5%

or

@2.5%

I would like to extract everything between '@' and '%'. The text in between these characters represents a number. Sometimes, the number contains a digit, and sometimes not.

Can anyone help me with a regular expression (so I can use the function regexp) to do so?

Many thanks already.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再回答此问题。

Answer 1

George 2016-9-8

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/302396-who-can-help-me-with-defining-a-regular-expression#answer_234212

在 MATLAB Online 中打开

str1 = '@5%';
str2 = '@2.5%';
regex = '\d*\.?\d+';
[s1 e1] = regexp(str1, regex);
[s2 e2] = regexp(str2, regex);
str1(s1:e1)
str2(s2:e2)
>> ans =
5
>> ans =
2.5

Play around with this. The regex captures 0 or more digits, 0 or 1 dots, and one or more digit. It ignores the @ and % signs. There are possibly weird cases where it may not work.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

George 2016-9-8

Warning, it will match on digits that aren't surrounded by the @ and % signs. If that's important you can modify the regex and adjust the ranges like str1(s1+1:e1-1).