PHP String Handling functions

1: String conversion

(1): Binary conversionA): Bin2Hex (string $str) binary to hex B): Hex2bin (String $str) hex-to-binary (2): Special character processing functionA): Addslashes (String $str) escapes special characters such as ' turn to \ '; b): Addcslashes (string $str) use the backslash in the C language style to escape the word such as ' to \ ' in the string; c): Stripslashes (String $str) restores the escape character D): Stripcslashes (String $str) restores the escape character e): Htmlspeciachars (string $str) special character processing F): Htmlspeciachars_decode (String $str) restores the path-handling special characters (3) uppercase lettersA): String Ucwords (String $str) converts the first letter of each word in a string to uppercase B): String Ucfirst (String $str) converts the first letter of the string to uppercase C): String Lcfirst (String $STR) Converts the first letter of the string to lowercase D): string Strtoupper (String $str) Converts the letter of the string to uppercase string Strtolower (string $str) Converts the letter of the string to lowercase (4) Character and ASCLL code conversionA): Char chr (char $str) convert ASCLL code to character B): int ord (int number) converts the character to ASCLL code (5) string EncryptionA:) string MD5 (string $str)

2: String Lookup

(1): int Strpos (String $str, String $needle, $offert) is case-sensitive, the return type is number-"find the character where the string is located $str the characters that are being looked up, $needle find the character, $offert set Starting position------homogeneous function------------stripos ()-Find the first occurrence of a string (case-insensitive) strrpos ()-Calculates the position of the last occurrence of the specified string in the target string Strripos ()- Calculates the last occurrence of the specified string in the target string (case-insensitive) (2): String Strstr (String $haystack, mixed $needle [, bool $before _needle = false]) Case-sensitive Before_needle if TRUE,STRSTR () returns the portion of the needle before the position in haystack. ------Homogeneous function------------stristr () is case insensitive (3): String STRRCHR (String $haystack, mixed $needle)-finds the last occurrence of a specified character in a string   Returns a portion of the haystack string, starting at the last occurrence of needle, until the end of haystack. (4): int Preg_match (String $pattern, String $subject [, Array & $matches [, int $flags = 0 [, int $offset = 0]]) Row a regular expression match (5): String substr ((string $string, int $start [, int $length]) substring of strings

3: String formatting and substitution

(1): String trim (string $haystack) removes whitespace from both ends------the same function------------LTrim () strips the Left blank RTrim () and removes the right blank chop (), etc.  Same as RTrim () (2): String Str_replace (mixed $search, mixed $replace, mixed $subject [, int & $count]);  If there are no special substitution requirements (such as regular expressions), you should use this function to replace ereg_replace () and Preg_replace (). -----------Similar functions-------------mixed substr_replace (mixed $string, mixed $replacement, mixed $start [, mixed $length] ) Mixed str_ireplace (mixed $search, mixed $replace, mixed $subject [, int & $count])

4: Output function 

echo

print () Pirnt_r () Var_dump () Four differences echo is similar to print usage, but echo can print multiple "," separate, pirnt_r mainly used to print objects and arrays, Var_dump () hit Information about the variables-----------similar functions------------printf () formatted output sprintf ()-Return a formatted string vprintf ()-Output formatted string sscanf ()-parses the input characters according to the specified format fscanf ()-Formats the input from the file

5: Formatting functions String Number_format (float $number, int $decimals = 0, string $dec _point = '. ', string $thousands _sep = ', ') string Money_format (string $format, float $number)6: Other functions

the int strlen () character length Boolean StrComp () character compares the character array explode (string $str, String $needle) to the string implode (array $ar R,string $needle) converts an array into characters equal to join

PHP String Handling functions