Quick check of PHP functions

This article mainly introduces the function of PHP fast check, has a certain reference value, now share to everyone, have the need for friends can refer to

Quick Check

String calculation 1.min () count minimum 2.max () Calculate maximum 3.ceil () up rounding 4.floor () down rounding 5.mt_rand () random number 6.trim () delete Except for the space around the string 7.rtrim () delete the right space alias: Chop () 8.ltrim () Delete left space 9.dirname () Get folder path from File path 10.str_repeat () health into a repeating string 11.str_split () Cut string 12.strrev () reverses the sequential string 13.wordwrap ($STR, 15) to specify a 15-byte newline 14.str_shuffle () random Scrambled string 15.parse_str ("Id=23&name=john%20adams", $myArray); convert URL parameter to array 16.number_format () thousand bits 17.strto Lower () converts the string to lowercase 18.strtoupper () converts the string to uppercase 19.ucfirst () to capitalize the first letter of the string 20.htmlentities () to output the HTML code directly 21 The. Strip_tags () filter HTML 22.quotemeta () replaces the special character escaping 23.substr_count () statistic string Occurrences 24.str_replace () string with 25.        STRRCHR () string intercept (last seen position) 26.STRCHR () string intercept alias Strstr 27.stripos () string lookup 28.strpos () string lookup (uppercase-sensitive) array 1.array_combine () takes an array as the key to the other array as the value 2.range (): Randomly produces an array of 3.compact (' variable name '): Generates an array with the variable named key and the value of the variable as the value 4.array_chun K () array split 5.array_mErge () merges an array 6.array_slice () array intercept 7.array_diff () to return an array of different values 8.array_intersect () returns the same value of the array 9.array_sear CH () finds the value of the string 10.array_splice () part of the array is removed with a different value instead of 11.in_array () to determine if the value exists in the array 12.array_key_exists () determine if the array exists This key 13.array_shift () pops the first element and returns 14.ARRAY_UNSHIF () to the front appending the element 15.array_pop () pops the last element 16.array_push () toward        Appends an element 17.shuffle () to a random scrambled array 18.array_reverse () to reverse the array 19.array_flip () key value substitution 20.array_keys () returns all keys 21.array_count_values () The number of occurrences of the statistic value 22.array_unique () removes the duplicate value 22.array_column ($arr, ' array of kin ', ' array of kin ') index array third        The 23.array_sum parameter causes the value of the third parameter to be used as the key to mix the values of the array () 24.assoc_unique () to remove the function file 1.fopen () to open File 2.fclose () Close file        3.file_exists () Determine if the file exists 4.filesize () gets the file size 5.is_readable () read whether the file is readable 6.is_writable () to determine if the file is writable        7.is_executable () Determine whether a file can execute 8.filectime () Gets the file creation time 9.filemtime () Get File update Time 10.fileatime () Get File access time    11.fread () Read file    12.opendir () Open folder 13.readdir () Read entry from directory handle 14.rmdir () Delete folder 15.unlink () Delete file 16.rename () Heavy Command folder                    or file time 17.date_default_timezone_set () sets the integer value of the variable for the default time zone 18.intval () for all datetime functions in a script 19. Other usage: ...                                Take the first value in the array Func_get_args () to get the information of the request header $this->test (... Func_get_args ()); Array_push () append $arr [] = [1]; dimensions are different