: Common php functions-string: some common functions that are compiled during php learning. this is a string function .; Helloworldecholtrim ($ str, #).; some common functions sorted out during php learning. this is a string function.
Header ("Content-Type: text/html; charset = UTF-8 ");
// Delete space on both sides or other predefined characters
$ Str = "# hello world @@";
Echo trim ($ str ,'#,@')."
"; // Hello world
Echo ltrim ($ str ,'#')."
"; // Hello world @@
Echo rtrim ($ str ,'@')."
"; // # Hello world
/* Chop () is the alias of rtrim */
// Return the directory part of the path
Echo dirname ("c:/testweb/home. php ")."
"; // C:/testweb
/** String generation and conversion */
// Fill the string in the specified string
$ Str = "hello world ";
Echo str_pad ($ str, 20, '.', STR_PAD_BOTH )."
"; //... Hello world .....
Echo str_pad ($ str, 20, '.', STR_PAD_LEFT )."
"; // ...... Hello world
Echo str_pad ($ str, 20, '.', STR_PAD_RIGHT )."
"; // Hello world .........
// Reuse the specified string
Echo str_repeat (".", 13 )."
";//.............
/* 13 indicates the number of duplicates */
// Splits the string into an array (which contains spaces and one space is 1 character)
$ Str = "my name is Junjun Liu ";
$ Str1 = str_split ($ str, 3 );
Print_r ($ str1 ); // Array ([0] => my [1] => nam [2] => e I [3] => s J [4] => unj [5] => un [6] => Liu)
// Reverse the string
$ Str = "imagecreatetruecolor ";
Echo strrev ($ str )."
"; // Roloceurtetaercegami
// Split the string according to the specified length
$ Str = "An example on a long word is: Supercalifragulisticlasdkjflasdjfalsdkakd ";
Echo wordwrap ($ str, 20 ,"
");
// Randomly disrupt all characters in the string (when a number is disrupted, the delimiter will also be disrupted)
$ Str = "a1, b2, c3 ";
Echo str_shuffle ($ str )."
"; // 1, ca32, B (random)
// Parse the string into a variable
$ Str = "first = value & arr [] = foo + bar & arr [] = baz ";
Parse_str ($ str );
Echo $ first ."
"; // Value
Echo $ arr [0]."
"; // Foo bar
Echo $ arr [1]."
"; // Baz
Print_r ($ arr); // Array ([0] => foo bar [1] => baz)
Parse_str ("id = 23 & name = John % 20 Adams", $ myArray );
Print_r ($ myArray); // Array ([id] => 23 [name] => John Adams)
// Format the number in a sub-location Group
Echo number_format ("1000000"); // 1,000,000.
Echo number_format ("1000000", 2); // 1,000,000.00
Echo number_format ("1000000", 2, "."); // 1.000.000, 00
// Case-sensitive conversion
Echo strtolower ('name'); // NAME
Echo strtoupper ('name'); // name
Echo ucfirst ('My name is Junjun Liu '); // my name is Junjun Liu
Echo ucwords ('My name is Junjun Liu '); // my Name Is Junjun Liu
// Html associated tags
// Convert string into HTML entity
$ Str = "John & 'Adams '";
Echo htmlentities ($ str, ENT_COMPAT); // John & 'Adams'
// Convert pre-defined characters to html encoding
Htmlspecialchars ($ str );
Echo"
";
// Replace \ n \ r and press enter in the string
Label to implement line feed output
$ String = "This \ r \ nis \ n \ ra \ nstring \ r ";
Echo nl2br ($ string );
/**
* This
* Is
*
* String
*/
// Remove HTML, XML, and PHP labels
$ Str ="AsdasdWoaini ";
Echo strip_tags ($ str); // asdasdwoaini
Echo"
";
// Add characters in the backslash escape string before the specified character
$ Str = "Hello, My name is John Adams .";
Echo addcslashes ($ str, 'M'); // Hello, \ my na \ me is John Ada \ ms
// Delete the addcslashes backslash
Echo stripcslashes ($ str); // Hello, my name is John Adams.
Echo"
";
// Add a backslash before a predefined character
$ Str = "Who's John Ad \ ams? ";
$ Str = addslashes ($ str );
Echo $ str; // Who \'s John Adams?
// Delete the backslash
Echo stripslashes ($ str )."
"; // Who's John Adams?
// Add a backslash before some predefined characters in the string (all characters are escaped)
$ Str = "hello world. (can you hear me ?) ";
Echo quotemeta ($ str )."
"; // Hello world \. \ (can you hear me \? \)
// ASCII return characters
Echo chr (34); // Return"
// Returns the ASCII value of the first character in the string.
Echo ord (abc); // 97
Echo"
";
/** String comparison */
/*
* 1: The former is large.
*-1: The latter is large.
* 0: Equal
*/
Echo "case-insensitive comparison of two strings:". strcasecmp ("abc", "abd ")."
"; //-1
Echo "compares two strings in case and case:". strcmp ("abd", "Abd ")."
"; // 1
Echo "compares two strings in case sensitivity:". strncmp ("abcd", "abcc", 2 )."
"; // 0/* 2 is to compare the size of the first n strings */
Echo "case-insensitive comparison of two strings:". strncasecmp ("abcd", "abcc", 4 )."
"; // 1
Echo "differentiate size (in natural order) write and compare two strings:". strnatcmp ("abc2", "abc12 ")."
"; //-1
Echo "no size difference (in natural order) write and compare two strings:". strnatcasecmp ("Abc8", "abc12 ")."
"; //-1
/* String cutting and splicing */
// Divide the string into small pieces (space calculation)
$ Str = "hello world ";
Echo chunk_split ($ str, 2, "#"); // he # ll # o # wo # rl # d #
// Cut string
$ First_token = strtok ('/something ','/');
$ Second_token = strtok ('/');
Var_dump ($ first_token); // string (9) "something"
Var_dump ($ second_token); // bool (false)
// Var_dump ($ first_token, $ second_token); (two variables are printed at the same time)
$ Str = "This is an/example string ";
$ Tok = strtok ($ str, "/"); // This is
Echo $ tok;
$ Str = "Thisisan/example string ";
$ Tok = strtok ($ str, "/"); // Thisisan
Echo $ tok;
// Use one string as the flag to separate another string
$ Data = "foo: *: 1023: 1000:/home/foo:/bin/sh ";
List ($ user, $ pass, $ uid, $ gid, $ gecos, $ home, $ shell) = explode (":", $ data );
Echo $ user; // foo
Echo $ pass ;//*
// Concatenate array values with reserved characters into strings
$ Array = array ('lastname', 'Email ', 'phone ');
$ A = implode (",", $ array );
Echo $ a; // lastname, email, phone
// Truncate the string
$ Str = "absadf ";
Echo substr ($ str, 2, 3); // sad
Echo substr ($ str,-4,-1); // sad
/* Search and replace strings */
// String replacement operation, case-sensitive str_replace (replaced font, replaced string, original string)
$ Str = "1, 2, 3: 4, 5: 6 ";
Echo str_replace (",", ":", $ str )."
"; // 1: 2: 3: 4: 5: 6
Echo str_replace (array (",", ":"), ";", $ str )."
"; // 1; 2; 3; 4; 5; 6
Echo str_replace (array (",", ":"), array (";", "#"), $ str )."
"; // 1; 2; 3 #4; 5 #6
// String replacement, case insensitive
$ Str = "abcdefg ";
Echo str_ireplace ("ABC", "xyz", $ str); // xyzdefg
// Count the number of times a string appears in another string substr_count (the string to be searched, the string to be searched, the start offset, and the maximum offset)
$ Str1 = "name ";
$ Str2 = "my name isname ";
Echo substr_count ($ str2, $ str1); // 2
// Replace a segment in the string with another string
$ Var = 'abcdefgh:/MNRPQR /';
Echo "Original: $ var \ N "; // Original: ABCDEFGH:/MNRPQR/
/* Use "bob" to replace the entire $ var. */
Echo substr_replace ($ var, 'Bob', 0 )."
\ N "; // bob
Echo substr_replace ($ var, 'Bob', 0, strlen ($ var ))."
\ N "; // bob
/* Insert "bob" to the beginning of $ var. */
Echo substr_replace ($ var, 'Bob', 0, 0 )."
\ N "; // bobABCDEFGH:/MNRPQR/
/* The following two examples use "bob" to replace "MNRPQR" in $ var ". */
Echo substr_replace ($ var, 'Bob', 10,-1 )."
\ N "; // ABCDEFGH:/bob/
Echo substr_replace ($ var, 'Bob',-7,-1 )."
\ N "; // ABCDEFGH:/bob/
/* Delete "MNRPQR" from $ var ". */
Echo substr_replace ($ var, '', 10,-1 )."
\ N "; // ABCDEFGH ://
// Returns the similarity between two strings.
$ Str1 = "abcdefgadfsa ";
$ Str2 = "acdrgwsaasdf ";
Echo (similar_text ($ str1, $ str2)/strlen ($ str1) * 100). "% "."
"; // 58.333333333333%
// String search
$ Str = "zhangsan ";
Echo strstr ($ str, "")."
"; // Angsan looks for the position where a appears from the beginning and intercepts it to the end (default: false) alias: strchr ()
Echo strstr ($ str, "a", true )."
"; // Zh start from the front and find the position where a appears and cut it forward
Echo strrchr ($ str, "")."
"; // An starts searching for a from the back and intercepts it to the end.
Echo strpos ($ str, "")."
"; // 2 obtain the position where the first occurrence of a string is
Echo strpos ($ str, "a", 3 )."
"; // 6 get the position where the string appears a from position 3
Echo strrpos ($ str, "")."
"; // 6 obtain the last position of a in the string
// Convert specified characters
$ Trans = array ("hello" => "hi", "hi" => "hello ");
Echo strtr ("hi all, I said hello", $ trans); // hello all, I said hi
Echo strtr ("baab", "AB", "01"); // 1001
$ Trans = array ("AB" => "01 ");
Echo strtr ("baab", $ trans); // ba01
/*
* Strstr (): Case Sensitive
* Stristr (): case-insensitive
*/
/*
* Strpos (): Case Sensitive
* Stripos () is case insensitive.
* Strrpos (): Case Sensitive
* Strripos (): case-insensitive
*
*/
// Return the length of the first substring in the specified character set that contains all the characters in the calculated string.
$ Var = strspn ("42 is the answer to the 128th question.", "1234567890 ");
Echo $ var; // 2 because '42' is the first consecutive character in subject that exists in '123.
// Obtain the length of the starting substring of the unmatched mask
$ A = strcspn ('abcd', 'apple'); var_dump ($ a); // int (0)
$ B = strcspn ('abcd', 'banana '); var_dump ($ a); // int (0)
$ C = strcspn ('hello', 'L'); var_dump ($ c); // int (2)
$ D = strcspn ('hello', 'World'); var_dump ($ d); // int (2)
/* String Statistics */
// Count the number of words contained in the string (the third parameter is ???????????????????????????? ????????????????????????)
$ Str = "My name is John ";
Echo str_word_count ($ str); // 4
Print_r (str_word_count ($ str, 1); // Array ([0] => My [1] => name [2] => is [3] => John)
Print_r (str_word_count ($ str, 2); // Array ([0] => My [3] => name [8] => is [11] => John)
// Count the string length
$ Str = 'AB CD ';
Echo strlen ($ str); // 7
// Count the number of occurrences of all letters in a string (0,255). The number of occurrences of each character is expressed by the corresponding ascii value.
$ Str = "aaaaasdfasdfwer; dlfgjjpoertuodbldbnlskjl; asfjoiwertowitwo ";
Echo"
";
//print_r(count_chars($str));
echo "
";
// Md5
$ Str = "hello4521 ";
Echo md5 ($ str); // 5af267d811a324fd640b7ad2199dfe14
Echo" ";
/*
Function getMd5 ($ str ){
Return md5 (md5 ($ s). "tri ");
}
*/
// Md5_file ()
$ Str = "ly. db ";
Echo md5_file ($ str); // 2f2b2262ed0732d497c90bf62af96240
The above describes common php functions-strings, including php and strings, and hopes to help those who are interested in PHP tutorials.
