A collection of built-in string operation functions in PHP and a collection of php string functions

A collection of built-in string operation functions in PHP and a collection of php string functions
1. Search for the character location function:

Strpos ($ str, search, [int]): // search for the first position of search in $ str starting from int; strrpos ($ str, search, [int]): // search for the last occurrence position of search in $ str starting from int

2. Extract sub-character functions (dual-byte)

Submit ($ str, int start [, int length]): // extract a [length string] starting from the strat position in $ str. Strstr ($ str1, $ str2): // search $ str2 from $ str1 (the first position) and extract the string from it to the end. If not, FALSE is returned. Stristr () // The function is the same as that of strstr, but it is case insensitive. Strrchr () // returns from the last searched character. Usage: get the file name in the path

3. Replace string

Str_replace (search, replace, $ str): from $ str, search for search to replace str_irreplace (search, replace, $ str): strtr ($ str, search, replace ): in this function, replace cannot be ""; substr_replace ($ Str, $ rep, $ start [, length]) $ str original string, $ rep new string after replacement, the starting position of $ start and the length of $ length. This parameter is optional.

4. query string length

int strlen($str)

5. Comparison of character Functions

Int strcmp ($ str1, $ str2): $ str1 >=< $ str2 is positive 1, 0,-1 respectively (string comparison
Strcasecmp () Same as above (case-insensitive
Strnatcmp ("4", "14") compares strings in natural order
Strnatcasecmp () is the same as above (case sensitive)

6. Split into array Functions

Str_split ($ str, len): splits $ str by len Length and returns an array.
Split (search, $ str [, int]): splits $ str by the search character and returns the number of times the array int is split.
Explode (search, $ str [, int])

7. Remove spaces:

ltrim、rtrim、trim

8. Space Function

Chunk_split ($ str, 2); add a space to the $ str string containing 2 characters;

9. Return the specified character or ascii

chr、ord

 

10. functions related to HTML code

Nl2br (): converts \ n to <br>.
Strip_tags ($ str [, '<p>']): // remove HTML and PHP tags
Htmlspecialchars ($ str [, parameter]): // the HTML code parameters output normally on the page are converted.

11. case-insensitive conversion functions

Strtolower ($ str) string to lowercase
Strtoupper ($ str) string to uppercase
Ucfirst ($ str) converts the first character of the function to uppercase.
Ucwords ($ str) converts the first letter of each word to uppercase

12. Database-related functions

Addslashes ($ str): converts single quotation marks ('), double quotation marks ("), backslash (\), and NUL strings \',\",\\.
Magic_quotes_gpc = On automatically escapes the get post cookie content
Get_magic_quotes_gpc () Check whether magic_quotes_gpc is enabled
Stripslashes () removes the backslash from the string

13. Connection Functions

Implode (str, $ arr) concatenates a string array into a string based on specified characters;
The implode () function has an alias function join.