PHP cheatsheet
PHP Array Functions array_diff (arr1, arr2 …) array_filter (arr, function) array_flip (arr) array_intersect (arr1, arr2 …) array_merge (arr1, arr2 …) array_pop (arr) array_push (arr, var1, var2 …) array_reverse (arr) array_search (needle, arr) array_walk (arr, function) count (count) in_array (needle, haystack) PHP String Functions crypt (str, salt) explode (sep, str) implode (glue, arr) nl2br (str) sprintf (frmt, args) strip_tags (str, allowed_tags) str_replace (search, replace, str) strpos (str, needle) strrev (str) strstr (str, needle) strtolower (str) strtoupper (str) substr (string, start, len) PHP Filesystem Functions clearstatcache () copy (source, dest) fclose (handle) fgets (handle, len) file (file) filemtime (file) filesize (file) file_exists (file) fopen (file, mode) fread (handle, len) fwrite (handle, str) readfile (file) PHP Date and Time Functions checkdate (month, day, year) date (format, timestamp) getdate (timestamp) mktime (hr, min, sec, month, day, yr) strftime (formatstring, timestamp) strtotime (str) time () PHP Regular Expressions Functions ereg (pattern, str) split (pattern, str) ereg_replace (pattern, replace, str) preg_grep (pattern, arr) preg_match (pattern, str) preg_match_all (pattern, str, arr) preg_replace (pattern, replace, str) preg_split (pattern, str) Regular Expressions Syntax regex meaning ^ Start of string $ End of string .