[php] PHP string "contains"

What would be the most efficient way to check whether a string contains a "." or not?

I know you can do this in many different ways like with regular expressions or loop through the string to see if it contains a dot (".").

You can use stristr() or strpos(). Both return false if nothing is found.

You can use these string functions,

strstr — Find the first occurrence of a string

stristr — Case-insensitive strstr()

strrchr — Find the last occurrence of a character in a string

strpos — Find the position of the first occurrence of a substring in a string

strpbrk — Search a string for any of a set of characters

If that doesn't help then you should use preg regular expression

preg_match — Perform a regular expression match