Preg_match differences?

Question

i want to ask, what is the meaning or difference between these two line?

2. if( preg_match_all('/\#([א-תÀ-ÿ一-龥а-яa-z0-9\-_]{1,50})/iu', $message, $matches, PREG_PATTERN_ORDER) ) {

3. if( preg_match_all('/\#([а-яa-z0-9\-_\x{4e00}-\x{9fa5}]{1,50})/iu', $message, $matches, PREG_PATTERN_ORDER) ) {

and what does the number 3 mean in this line? (Arrow pointing)

if( preg_match_all('/\@([a-zA-Z0-9\-_\x{4e00}-\x{9fa5}]{->3,30})/u', $message, $matches, PREG_PATTERN_ORDER) ) {

Thanks!

Answer 1

I'll answer the 2nd part of your question:

The {3,30} in the regex means quantifier for a min of 3 and a max of 30 repetitions.

• a* means zero or more a
• a+ means one or more a
• a? means zero or one a
• a{1} means exactly one a same as just a
• a{1,} means one or more a same as a+
• a{1,3} means min of one and max of 3 a's

you can have any complex regex in place of a. Example: [a-zA-Z]{3,30} would mean at least 3 and at max 30 of any of the alphabets.