Php/docs/pcre.examples
From Get docs
Examples
Example #1 Examples of valid patterns
/<\/\w+>/
|(\d{3})-\d+|Sm
/^(?i)php[34]/
{^\s+(\s+)?$}
Example #2 Examples of invalid patterns
-
/href='(.*)'
- missing ending delimiter -
/\w+\s*\w+/J
- unknown modifier 'J' -
1-\d3-\d3-\d4|
- missing starting delimiter