What does preg_match isU mean? preg_matchisu represents _ PHP Tutorial

What is the meaning of preg_match isU, and preg_matchisu. What is the meaning of preg_match isU? preg_matchisu indicates the (. *) isU following the regular expression. what does the isU parameter mean? This is the modifier in the regular expression. I is used to search for uppercase and lowercase letters at the same time, s is the isU of the circle preg_match, and preg_matchisu represents

What does the/(. *)/isU and "isU" parameter after the regular expression mean?
This is the modifier in the regular expression.
I is used to search for uppercase and lowercase letters at the same time,
S indicates that the dot (.) matches all characters, including line breaks. if s is not set, the line breaks are not included.
U reverses the value of the matching quantity so that it is not the default repetition, but becomes behind "?" To be repeated.

What is the meaning of the/(. *)/isU and isU parameters after the limit regular expression? This is the modifier in the regular expression. I is used to search for uppercase and lowercase letters, and s is a circle...