Today I learn regular expressions
1 * and?
Look at the most basic regular symbol ---- *? ------
* Wildcard matches zero or more characters
? Wildcard matches the file name of zero or one character
There are two classical terms lazy matching and greedy matching involves two combined symbols wherein (*) and (* ?.)
(*) Are greedy match on behalf of as many matches between the characters and therefore it h l and all the characters match out
(. *?) Are lazy match as few characters, but matching to match all characters
(. +?) Represents the number of characters to match the middle character is greater than or equal 1
(. ??) This match is repeated once and zero times
The number of which we are also their own definition of
. {n, m}? represents the number of n from the number of matched characters m
2. Regular of basic grammar
For ^ [0-9a-zA-Z _- ] + abcdef $