PHP String functions

_PHP_list_of_string_functions

addcslashes()       	        Returns a string with backslashes in front of the specified characters
addslashes()	                Returns a string with backslashes in front of predefined characters
bin2hex()       	            Converts a string of ASCII characters to hexadecimal values
chop()	                      Removes whitespace or other characters from the right end of a string
chr()	                        Returns a character from a specified ASCII value
chunk_split()       	        Splits a string into a series of smaller parts
convert_cyr_string()          Converts a string from one Cyrillic character-set to another
convert_uudecode()        	  Decodes a uuencoded string
convert_uuencode()	          Encodes a string using the uuencode algorithm
count_chars()	                Returns information about characters used in a string
crc32()	                      Calculates a 32-bit CRC for a string
crypt()	                      One-way string encryption (hashing)
echo()	                      Outputs one or more strings
explode()	                    Breaks a string into an array
fprintf()	                    Writes a formatted string to a specified output stream
get_html_translation_table()  Returns the translation table used by htmlspecialchars() and htmlentities()
hebrev()	                    Converts Hebrew text to visual text
hebrevc()	                    Converts Hebrew text to visual text and new lines (\n) into <br>
hex2bin()	                    Converts a string of hexadecimal values to ASCII characters
html_entity_decode()	        Converts HTML entities to characters
htmlentities()              	Converts characters to HTML entities
htmlspecialchars_decode()	    Converts some predefined HTML entities to characters
htmlspecialchars()	          Converts some predefined characters to HTML entities
implode()	                    Returns a string from the elements of an array
join()	                      Alias of implode()
lcfirst()	                    Converts the first character of a string to lowercase
levenshtein()	                Returns the Levenshtein distance between two strings
localeconv()	                Returns locale numeric and monetary formatting information
ltrim()	                      Removes whitespace or other characters from the left side of a string
md5()	                        Calculates the MD5 hash of a string
md5_file()                  	Calculates the MD5 hash of a file
metaphone()	                  Calculates the metaphone key of a string
money_format()	              Returns a string formatted as a currency string
nl_langinfo()	                Returns specific local information
nl2br()	                      Inserts HTML line breaks in front of each newline in a string
number_format()	              Formats a number with grouped thousands
ord()	                        Returns the ASCII value of the first character of a string
parse_str()	                  Parses a query string into variables
print()	                      Outputs one or more strings
printf()	                    Outputs a formatted string
quoted_printable_decode()	    Converts a quoted-printable string to an 8-bit string
quoted_printable_encode()	    Converts an 8-bit string to a quoted printable string
quotemeta()	                  Quotes meta characters
rtrim()	                      Removes whitespace or other characters from the right side of a string
setlocale()	                  Sets locale information
sha1()	                      Calculates the SHA-1 hash of a string
sha1_file()	                  Calculates the SHA-1 hash of a file
similar_text()	              Calculates the similarity between two strings
soundex()	                    Calculates the soundex key of a string
sprintf()	                    Writes a formatted string to a variable
sscanf()	                    Parses input from a string according to a format
str_getcsv()	                Parses a CSV string into an array
str_ireplace()	              Replaces some characters in a string (case-insensitive)
str_pad()	                    Pads a string to a new length
str_repeat()	                Repeats a string a specified number of times
str_replace()	                Replaces some characters in a string (case-sensitive)
str_rot13()	                  Performs the ROT13 encoding on a string
str_shuffle()	                Randomly shuffles all characters in a string
str_split()	                  Splits a string into an array
str_word_count()	            Count the number of words in a string
strcasecmp()	                Compares two strings (case-insensitive)
strchr()	                    Finds the first occurrence of a string inside another string (alias of strstr())
strcmp()	                    Compares two strings (case-sensitive)
strcoll()	                    Compares two strings (locale based string comparison)
strcspn()	                    Returns the number of characters found in a string before any part of some specified 
                                characters are found
strip_tags()	                Strips HTML and PHP tags from a string
stripcslashes()	              Unquotes a string quoted with addcslashes()
stripslashes()	              Unquotes a string quoted with addslashes()
stripos()                   	Returns the position of the first occurrence of a string inside another string (case-insensitive)
stristr()	                    Finds the first occurrence of a string inside another string (case-insensitive)
strlen()	                    Returns the length of a string
strnatcasecmp()	              Compares two strings using a "natural order" algorithm (case-insensitive)
strnatcmp()                 	Compares two strings using a "natural order" algorithm (case-sensitive)
strncasecmp()               	String comparison of the first n characters (case-insensitive)
strncmp()	                    String comparison of the first n characters (case-sensitive)
strpbrk()                   	Searches a string for any of a set of characters
strpos()	                    Returns the position of the first occurrence of a string inside another string (case-sensitive)
strrchr()	                    Finds the last occurrence of a string inside another string
strrev()	                    Reverses a string
strripos()	                  Finds the position of the last occurrence of a string inside another string (case-insensitive)
strrpos()	                    Finds the position of the last occurrence of a string inside another string (case-sensitive)
strspn()	                    Returns the number of characters found in a string that contains only characters 
                                from a specified charlist
strstr()	                    Finds the first occurrence of a string inside another string (case-sensitive)
strtok()	                    Splits a string into smaller strings
strtolower()	                Converts a string to lowercase letters
strtoupper()	                Converts a string to uppercase letters
strtr()	                      Translates certain characters in a string
substr()                    	Returns a part of a string
substr_compare()	            Compares two strings from a specified start position (binary safe and optionally case-sensitive)
substr_count()	              Counts the number of times a substring occurs in a string
substr_replace()	            Replaces a part of a string with another string
trim()                      	Removes whitespace or other characters from both sides of a string
ucfirst()                   	Converts the first character of a string to uppercase
ucwords()	                    Converts the first character of each word in a string to uppercase
vfprintf()	                  Writes a formatted string to a specified output stream
vprintf()	                    Outputs a formatted string
vsprintf()	                  Writes a formatted string to a variable
wordwrap()	                  Wraps a string to a given number of characters

php_addcslashes.php

<?php

  //The addcslashes() function returns a string with backslashes in front of the specified characters.

  //Note: The addcslashes() function is case-sensitive.

  //Note: Be careful using addcslashes() on 
    # 0 (NULL),
    # r (carriage return),
    # n (newline),
    # f (form feed),
    # t (tab) and v (vertical tab). 
    #In PHP, \0, \r, \n, \t, \f and \v are predefined escape sequences.
    
  //Syntax
    # addcslashes(string,characters);


  //Add backslashes to certain characters in a string:
  $str = "Welcome to my humble Homepage!";
  echo $str."<br>";
  echo addcslashes($str,'m')."<br>";
  echo addcslashes($str,'H')."<br>";

  //Add backslashes to a range of characters in a string:
  $str = "Welcome to my humble Homepage!";
  echo $str."<br>";
  echo addcslashes($str,'A..Z')."<br>";
  echo addcslashes($str,'a..z')."<br>";
  echo addcslashes($str,'a..g');
?>
  
</body>
</html>

php_str_replace.php

<?php
  //str_replace() function replaces some characters with some other characters in a string.

  //The example below replaces the text "world" with "Dolly":
  echo str_replace("world", "Dolly", "Hello world!"); 
  // outputs Hello Dolly!
  
?>

php_str_word_count.php

<?php
  //str_word_count() function counts the number of words in a string.
  echo str_word_count("Hello world!"); // outputs 2
?>

php_strlen.php

<?php
  //strlen() function returns the length of a string.
  echo strlen("Hello world!"); // outputs 12
?>

php_strpos.php

<?php
  //The PHP strpos() function searches for a specific text within a string.
  //If a match is found, the function returns the character position of the first match. 
  //If no match is found, it will return FALSE.

  //The example below searches for the text "world" in the string "Hello world!":
  echo strpos("Hello world!", "world"); // outputs 6
?>

php_strrev.php

<?php
  //strrev() function reverses a string
  echo strrev("Hello world!"); // outputs !dlrow olleH
?>