Question

I am trying to find whether a pattern exists in a string.

Pattern I want to check is:

String starting with space or “#”,
then with specific string “value1” followed by space or tab,
then “value2” and again space or tab,
ends with “value3”.

Here a sample string to check:

String str = "#  value1   values2 value3";

I tried the following regular expression, but it did’t work:

str.matches("^\\s+#\\s+value1\\s+value2\\s+value3");

The above pattern always returns me false. Please help with regular expression.
Any help will be really appreciated.

Answer 1

Try this: –

str.matches("^[ #]value1\\s+value2\\s+value3$");

[ #] – matches a space or #

\\s+ – matches 1 or more spaces. So, it would match a space or tab

NOTE: – You have values2 instead of value2 in your string.

Also, your example string you posted, has both a space and a # at the starting. But you said the string starts with a space or a #. So, it will match your string, if you remove that space after the first #, or your # before your space, which is according to what you wrote.

If you want to match a space and a # at the starting of your string, as in your current String you posted. You need to use this regex: –

str.matches("^[ #]\\svalue1\\s+value2\\s+value3$");