1. String substitution functionStr_replace () replaces a string or array element, is case-sensitive, and the 4th parameter is optional for statistical The number of replacements. Str_ireplace () case- insensitive STRTR () replaces any character in a string2. String comparison functionstrcmp () compares strings if equal returns 0 if the string 1< string 2 returns 1 otherwise returns 1
strcasecmp () case insensitive string comparison
strnatcmp () compare by natural number
strncmp () specifying the number of digits for string comparisons
Similar_text () compares how many characters are equal for two strings, and the third parameter returns a variable that is a percentage similar to the 2 string
3. String statistic function Substr_count () to find the number of occurrences of a string in another string, you can specify the starting lookup location for the lookup length.
From for notes (Wiz)
String manipulation function 3
