A "correction mode" is a matching pattern for a regular expression, similar to a phone's mode (family mode, conferencing mode, and so on):
These include the following:
"Greedy match"-refers to the result when the result of the match is ambiguous (multiple results appear), it will choose the longest result;
"Lazy Match (U)"-refers to the result when the matching result is ambiguous (there are multiple results), it will choose the shortest result;
"I"--ignores the case of the English letters in the regular expression;
"X"-ignores whitespace in regular expressions;
"S"--let meta-characters '. ' Matches all characters, including line breaks;
If no correction mode is specified for the regular expression, then the regular expression uses the greedy mode by default;
The above describes the PHP regular expression-correction mode, including the aspects of the content, I hope to be interested in PHP tutorial friends helpful.
