explode — use one string to split another string
array explode ( string $delimiter , string $string [, int $limit ] )
implode — converts a one-dimensional array of values to a string
string implode ( string $glue , array $pieces )
htmlspecialchars — Convert special characters to HTML entities (XXS)
string htmlspecialchars ( string $string )
htmlspecialchars_decode — converts special HTML entities back to normal characters (as opposed to htmlspecialchars)
string htmlspecialchars_decode ( string $string )
strip_tags — strips HTML and PHP tags from strings (unlike htmlspecialchars, strip_tags strips tags directly, while the former escapes them to other characters)
string strip_tags ( string $str [, string $allowable_tags ] )
md5 — Calculates the MD5 hash of a string
string md5 ( string $str [, bool $raw_output = false ] )
nl2br — inserts HTML newlines before all newlines in the string (converts \n or \r\n not recognized by browsers to </br>)
string nl2br ( string $string [, bool $is_xhtml = TRUE ] )
trim — remove whitespace (or other characters) at the beginning and end of a string
string trim ( string $str [, string $character_mask = " \t\n\r\0\x0B" ] )
strpos — find the first occurrence of a string ( stripos is not case sensitive) ( usually used to tell if a string contains another string )
int stripos ( string $haystack , string $needle [, int $offset = 0 ] )
strrpos — Calculates the position of the last occurrence of the specified string in the target string
int strrpos ( string $haystack , string $needle [, int $offset = 0 ] )
strlen — get the length of the string (can also be used to determine whether the string is empty)
int strlen ( string $string )
strtolower — converts a string to lowercase
string strtolower ( string $string )
strtoupper — convert a string to uppercase
string strtoupper ( string $string )
substr_count — count the number of occurrences of a string
int substr_count ( string $haystack , string $needle [, int $offset = 0 [, int $length ]] )
substr — returns a substring of the string (returns the substring of the string specified string by the start and lenth parameters)
string substr ( string $string , int $start [, int $length ] )
string
Enter a string. Must have at least one character.
start
If start non-negative, the returned string will start string at start position 0, counting from 0. For example, in the string " abcdef ", the character in position 0 is " a ", the character in position 2 is " c ", and so on.
If start negative, the returned string will start string at the first character from the end start .
Will return if string the length is less than .startFALSE
length
If a positive number is provided length, the returned string will be start up to and including length characters (depending on string the length) starting at .
If a negative number is provided length, the characters string at the end length will be omitted ( start if negative number is counted from the end of the string). If start not in this text, it will return FALSE.
If a value of 0 , FALSE or NULL , is provided length, then an empty string will be returned.
If not provided length, the returned substring will start start at position until the end of the string.
str_replace — Substring replacement (use str_ireplace ignoring case )
mixed str_replace ( mixed $search , mixed $replace , mixed $subject [, int &$count ] )
search
The target value of the lookup, which is the needle . An array can specify multiple targets.
replace
search replacement value. An array can be used to specify multiple replacements.
subject
Array or string to perform the replacement on. That is haystack .
If it subject is an array, the replace operation will traverse the whole subjectand the return value will also be an array.
count
If specified, its value will be set to the number of times the replacement occurred.