PHP string built-in function summary

1.STRCMP ($str 1, $str 2) If equal returns 0, $str 1> $str 2 returns 1, $STR 1< $str 2 Returns-1 (this is greater than and less than just the position of the comparison, according to the ASCII code table).

2.STRNCMP ($str 1, $str 2, $length) intercept $str1 and $STR2 respectively from a string of 0-length $length, and the output is the same as the first example.

3.strstr ($STR, $need, bool $return _before=false) An important string lookup function is equivalent to STRCHR (), a string that $str operation, $need the string to find, $return _before Whether to return the string $need before $str, the return value of this function is the first occurrence of the $need string in $str to the last position of the $str.

4.STRRCHR ($str, $need) $need The last occurrence of the position to the end of the $str in the string $str

5. $strpos ($STR, $need) The first occurrence of the $need position in the $str, where $str is not found returns NULL, case-insensitive stripos ()

6.strrpos ($str, $need) The location of the last occurrence of $need in $str, no return null found, case insensitive can be strripos ()

7.STRPBRK ($str, $charlist) $str the string to manipulate, $charlist the character set ($charlist = ' ABCDE '), and find any character in the $charlist in $str, Returns the remainder of the beginning of the position where the first occurrence of the specified character

8.substr ($str, $start, $length) an important string intercept function that intercepts a string in the $start position at the beginning of $length in $str

9.explode ($delimiter, $str, $limit =null) string-splitting function, $delimiter as a delimiter, $str as an operator, delimiter cannot be empty, NULL returns FALSE, and an array is returned by default.

10.implode ($glue, array $pieces) an important string connection function that $pieces each element in the array to create a new string return with the connector $gule, equivalent to the join () function.

11.str_split ($STR, $length) splits the $STR and returns the array according to the length specified by $length, noting that Mb_split () can be better compatible with Chinese.

12.str_replace ($search, $replace, $str) Important string substitution functions, $search in $STR are replaced with $replace.

13.substr_replace ($str, $replacement, $start, $length =null) substring substitution function, $str a substring of $length length from the beginning of the $start is replaced with $replacement.

14.str_repeat ($STR, $times) generates a new string and returns $STR repeating $times times

15.str_pad ($str, $pad _length, $pad _str, $pad _type) string fill function, $str the manipulated string, $pad _length the length to fill, $pad _str the string to fill, $pad _ Type:str_pad_left, and so on, indicates where the string is populated.

16.ord (String $char) returns the ASCII corresponding code value chr (int $ascii) returns the ASCII code value corresponding to the string

17.strrev ($STR) string inversion

18.strip_tags ($str, $remain _tags), delete HTML or XML tags as long as <> will be filtered out, you can $remain_tags set the label you want to keep

19.NL2BR ($STR) adding </br> wrapping in front of a new line

Add: The Characters of MB (multibyte) Chinese or some other text are made up of multiple bytes, and the previous function of string splitting and so on does not start with a single byte, which will result in a non-conforming operation for Chinese characters. So mbstring provides a good way to operate.