Regular expression question mark colon?: Using __ Regular expressions

(?: pattern) matches patterns without capturing the bracket, but does not capture the matching result.    (pattern) is a capturing bracket. Match pattern, match pattern and capture results, automatically get group number (?<name> pattern) match pattern, match pattern and capture results, set name to use parentheses for group names to specify a subexpression, the text that matches the subexpression (that is, what this group captures) can be further processed in an expression or other program.      By default, each capturing group automatically owns a group number, which is left to right, is marked with the left parenthesis of the group, the first group that appears is 1, the second is 2, and so on.         If both the normal and named capture groups exist in the regular expression, the number of the capturing group should be paid special attention to, the number rule is to number the normal capturing group first, then the named Capture Group. To avoid too many parentheses to clutter up numbers, and to avoid unwanted capture efficiencies, you can use a non-capture bracket when you don't need to capture just the group you want to specify. The non-capture bracket in question is used for this purpose.