PHP extension text processing-string and string functions are all string functions processed in various ways. There are also some special chapters in the regular expression and URL processing sections.
For more information about the operating mechanism of strings, especially about single quotes, double quotation marks, and escape sequences, see string entries.
String functions:
Addcslashes-escape characters in strings using backslash in the C-language style
Addslashes-use a backslash to reference a string
Bin2hex-Convert binary data to hexadecimal representation
Alias of chop-rtrim
Chr-return the specified character
Chunk_split-splits a string into small parts
Convert_cyr_string-converts a character from one Cyrillic to another.
Convert_uudecode-decodes a uencode string
Convert_uuencode-encode a string using uuencode
Count_chars-returns the characters used by the string.
Crc32-calculate the crc32 polynomial of a string
Crypt-unidirectional String hash
Echo-output one or more strings
Explode-use one string to separate another string
Fprintf-Write formatted strings to the stream
Get_html_translation_table-return the conversion table after using htmlspecialchars and htmlentities
Hebrev-convert the logical sequence Hebrew (logical-Hebrew) to the visual sequence Hebrew (visual-Hebrew)
Hebrevc-converts the logical sequence Hebrew (logical-Hebrew) to the visual sequence Hebrew (visual-Hebrew), and converts the line break
Hex2bin-convert a hexadecimal string to a binary string
Html_entity_decode-Convert all HTML entities to their applicable characters
Htmlentities-Convert all applicable characters to HTML entities
Htmlspecialchars_decode-converts special HTML objects back to common characters
Htmlspecialchars-Convert special characters to HTML entities
Implode-convert the value of a one-dimensional array to a string
Join-alias implode
Lcfirst-lowercase for the first character of a string
Levenshtein-calculates the editing distance between two strings
Localeconv-Get numeric formatting information
Ltrim-removes spaces (or other characters) starting with a string)
Md5_file-calculate the MD5 hash value of the 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 the HTML line feed mark before all new lines of the string
Number_format-format a number using a thousands separator
Ord-returns the ASCII value of a character.
Parse_str-parses a string into multiple variables.
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-removes white spaces (or other characters) at the end of a 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 between two strings
Soundex-Calculate the soundex key of a string
Sprintf-Return a formatted string
Sscanf-parses input characters according to the specified format
Str_getcsv-parses a CSV string as an array
Case-insensitive version of str_ireplace-str_replace
Str_pad-use another string to fill the string with the specified length
Str_repeat-repeat a string
Str_replace-substring replacement
Str_rot13-execute the ROT13 conversion on the string
Str_shuffle-randomly disconnects a string
Str_split-convert string to array
Str_word_count-returns the usage of words in the string
Strcasecmp-binary security comparison string (case insensitive)
Strchr-alias strstr
Strcmp-binary security string comparison
Strcoll-string comparison based on region settings
Strcspn-get the length of the starting substring of the unmatched mask
Strip_tags-remove HTML and PHP tags from strings
Stripcslashes-references a string escaped using addcslashes
Stripos-locate the first occurrence of a string (case insensitive)
Stripslashes-references a reference string
The stristr-strstr function is case-insensitive.
Strlen-get the string length
Strnatcasecmp-use the natural order algorithm to compare strings (case insensitive)
Strnatcmp-use a natural sorting algorithm to compare strings
Strncasecmp-several characters starting with a binary security comparison string (case insensitive)
Strncmp-several characters starting with a binary security comparison string
Strpbrk-find any character of a group of characters in a string
Strpos-locate the first occurrence of a string
Strrchr-find the last occurrence of a specified character in the string
Strrev-reverse 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 last occurrence of the specified string in the target string
Strsps-calculate the length of the first substring in a string that contains all characters in the specified character set.
Strstr-first appearance of the search string
Strtok-mark the delimiter
Strtolower-converts a string to lowercase
Strtoupper-converts a string to uppercase
Strtr-conversion of specified characters
Substr_compare-binary secure comparison string (compare the specified length from the offset position)
Substr_count-calculates the number of times a string appears.
Substr_replace-replace the substring of a string
Substr-returns the substring of the string.
Trim-removes spaces (or other characters) at the beginning and end of the string)
Ucfirst-converts the first letter of a string to uppercase
Ucwords-converts the first letter of each word in a string to uppercase
Vfprintf-Write formatted strings to the stream
Vprintf-output formatted string
Vsprintf-returns the formatted string
Wordwrap-the interrupt string is a specified number of strings.