minor #16424 Moving RexExp search to its own heading (ThomasLandauer)

This PR was merged into the 5.3 branch.

Discussion
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Moving RexExp search to its own heading

See symfony/symfony#45032 (comment)

I wanted to create a heading ("Search Using a Regular Expression") for this. Is `~~~~` the lowest level already? If yes, I'd suggest to drop the "Method Reference" heading, and promote all included "Methods to..." headings one level.

Commits
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4efdd76 Include match examples in the code block
683a671 Moving RexExp search to its own heading

Author: wouterj

components/string.rst

@@ -318,9 +318,15 @@ Methods to Search and Replace
     // checks if the string contents are exactly the same as the given contents
     u('foo')->equalsTo('foo'); // true
 
-    // checks if the string content match the given regular expression
+    // checks if the string content match the given regular expression.
+    // You can pass flags for preg_match() as second argument. If PREG_PATTERN_ORDER
+    // or PREG_SET_ORDER are passed, preg_match_all() will be used.
     u('avatar-73647.png')->match('/avatar-(\d+)\.png/');
     // result = ['avatar-73647.png', '73647']
+    u('avatar-73647.png')->match('/avatar-(\d+)(-\d+)?\.png/', \PREG_UNMATCHED_AS_NULL);
+    // result = ['avatar-73647.png', '73647', null]
+    u('206-555-0100 and 800-555-1212')->match('/\d{3}-\d{3}-\d{4}/', \PREG_PATTERN_ORDER);
+    // result = [['206-555-0100', '800-555-1212']]
 
     // checks if the string contains any of the other given strings
     u('aeiou')->containsAny('a');                 // true