These are functions that manipulate strings in various ways. There are also dedicated chapters on regular expressions and URL processing.

For information about the operation mechanism of strings, especially information about single quotes, double quotes, and escape sequences, see the string entry.

Comprehensive collection of string functions:

addcslashes — Use backslashes to escape characters in strings in C language style

addslashes — Use backslashes to quote strings

bin2hex — Convert binary data to hexadecimal Represents

chop — Alias ??for rtrim

chr — Returns the specified character

chunk_split — Splits the string into small pieces

convert_cyr_string — Converts characters from one Cyrillic character to another

convert_uudecode — Decodes a uuencode Encoded string

convert_uuencode — Use uuencode to encode a string

count_chars — Return information about the characters used in the string

crc32 — Calculate the crc32 polynomial of a string

crypt — One-way string hashing

echo — Output one or more strings

explode — Use one string to split another string

fprintf — Write the formatted string to the stream

get_html_translation_table — Return the translation table after using htmlspecialchars and htmlentities

hebrev — Convert logical-Hebrew to visual-Hebrew

hebrevc — Convert logical-Hebrew to visual-Hebrew text (visual-Hebrew), and convert newlines

hex2bin — Convert hexadecimal strings to binary strings

html_entity_decode — Convert all HTML entities to their applicable characters

htmlentities — Convert all applicable characters to HTML entities

htmlspecialchars_decode — Convert special characters to HTML entities

htmlspecialchars — Convert special characters to HTML entities

implode — Convert the values ??of a one-dimensional array into a string

join — Alias ??implode

lcfirst — Make a character The first character of the string is lowercase

levenshtein — Calculate the edit distance between two strings

localeconv — Get numeric formatting information

ltrim — Remove the blank characters (or other characters) at the beginning of the string

md5_file — Calculate MD5 hash value of a specified file

md5 — Calculate the MD5 hash value of a string

metaphone — Calculate the metaphone key of a string

money_format — Formats a number as a currency string

nl_langinfo — Query language and locale information

nl2br — Insert HTML newline mark before all new lines in the string

number_format — Format a number with thousand separators

ord — Return the ASCII code value of the character

parse_str — Parse the string into multiple Variable

print — Output string

printf — Output formatted string

quoted_printable_decode — Convert a quoted-printable string to an 8 bit string

quoted_printable_encode — Convert a 8 bit string to a quoted-printable string

quotemeta — Quote meta characters

rtrim — Remove blank characters (or other characters) at the end of the string

setlocale — Set locale information

sha1_file — Calculate the sha1 hash value of the file

sha1 — Calculate the sha1 hash value of the string

similar_text — Calculate the similarity of two strings

soundex — Calculate the soundex key of a string

sprintf — Return a formatted string

sscanf — Parse the input characters according to the specified format

str_getcsv — Parse CSV string For an array

str_ireplace — Case-ignoring version of str_replace

str_pad — Fill a string with another string to the specified length

str_repeat — Repeat a string

str_replace — Substring replacement

str_rot13 — For characters String execution ROT13 conversion

str_shuffle — Randomly shuffle a string

str_split — Convert a string into an array

str_word_count — Return the usage of words in a string

strcasecmp — Binary safe comparison of strings (case-insensitive )

strchr — alias strstr

strcmp — Binary safe string comparison

strcoll — Locale-based string comparison

strcspn — Get the length of the starting substring of a non-matching mask

strip_tags — From characters Remove HTML and PHP tags from a string

stripcslashes — Dequote a string escaped using addcslashes

stripos — Find the first occurrence of a string (case-insensitive)

stripslashes — Dequote a quoted string

stristr — A case-ignoring version of the strstr function

strlen — Get the length of a string

strnatcasecmp — Compare strings using the “natural ordering” algorithm (case-insensitive)

strnatcmp — Compare strings using the natural ordering algorithm

strncasecmp — Binary-safe comparison of several characters at the beginning of the string (case-insensitive)

strncmp — Binary safe comparison of several characters at the beginning of a string

strpbrk — Find any character in a set of characters in a string

strpos — Find the first occurrence of a string

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

strrev — Reverse a string

strripos — Calculate the position of the last occurrence of the specified string in the target string (case-insensitive)

strrpos — Calculate the position of the specified string in the target string The position of the last occurrence

strspn — Calculate the length of the first substring in the string where all characters exist in the specified character set.

strstr — Find the first occurrence of a string

strtok — Mark split string

strtolower — Convert the string to lowercase

strtoupper — Convert the string to uppercase

strtr — Convert the specified character

substr_compare — Binary Safely compare strings (compare specified lengths from offset positions)

substr_count — Count the number of occurrences of a string

substr_replace — Replace a substring of a string

substr — Return a substring of a string

trim — Remove a string Blank characters (or other characters) at the beginning and end

ucfirst — Convert the first letter of the string to uppercase

ucwords — Convert the first letter of each word in the string to uppercase

vfprintf — Write the formatted string Incoming stream

vprintf — Output formatted string

vsprintf — Return formatted string

wordwrap — Break the string into a specified number of words