Работа со строками

Краткое содержание лекции

Теоретические задания | Практические задания

Возможное представление строки:

• single quoted
• double quoted
• heredoc syntax
• nowdoc syntax (since PHP 5.3.0)

Возможность обращения к символу строки.

Функции по работе со строками

Полный список функций доступен в документации.

Функции вывода / ввода данных

• void echo ( string $arg1 [, string $... ] )
  • конструкция языка, а не функция
  • echo $a;
  • echo ($a, $b); - невалидно
  • echo $a, $b; - валидно
  • <?=$a;?>
• int print ( string $arg )
  • конструкция языка, а не функция
  • только один аргумент
  • возвращает всегда 1
• int printf ( string $format [, mixed $args [, mixed $... ]] )
  • выводит на экран отформатированную строку
  • возвращает длину выведенной строки
• string sprintf ( string $format [, mixed $args [, mixed $... ]] )
• int fprintf ( resource $handle , string $format [, mixed $args [, mixed $... ]] )
• int vprintf ( string $format , array $args )
• string vsprintf ( string $format , array $args )
• int vfprintf ( resource $handle , string $format , array $args )
• mixed sscanf ( string $str , string $format [, mixed &$... ] )

lowercase / uppercase

• string strtolower ( string $str )
• string strtoupper ( string $string )
• string lcfirst ( string $str )
• string ucfirst ( string $str )
• string ucwords ( string $str )

Поиск / замена / "фильтрация" строк

• strlen
  • int strlen ( string $string )
  • strlen(array(2));
  • возвращает кол-во байтов, а не символов в строке
• int strpos ( string $haystack , mixed $needle [, int $offset = 0 ] )
• string strstr ( string $haystack , mixed $needle [, bool $before_needle = false ] ) / strchr

• string strrchr ( string $haystack , mixed $needle )

• string strtok ( string $str , string $token )

• strtr делает замену символов в строке

  • string strtr ( string $str , string $from , string $to )
  • string strtr ( string $str , array $replace_pairs )

• string strrev ( string $string )

Работа с подстроками

• string substr ( string $string , int $start [, int $length ] )
• mixed substr_replace ( mixed $string , mixed $replacement , mixed $start [, mixed $length ] )
• int substr_count ( string $haystack , string $needle [, int $offset = 0 [, int $length ]] )

Работа с хешами

• string sha1 ( string $str [, bool $raw_output = false ] )
• string sha1_file ( string $filename [, bool $raw_output = false ]
• md5 — Calculate the md5 hash of a string
• md5_file — Calculates the md5 hash of a given file

"Работа" с символами

• string chr ( int $ascii )
• int ord ( string $string )

Обработка строк (лишних отступов)

• string trim ( string $str [, string $charlist ] )
• string ltrim ( string $str [, string $charlist ] )
• string rtrim ( string $str [, string $charlist ] ) / chop

"Полезное"

• string str_shuffle ( string $str )
• array str_split ( string $string [, int $split_length = 1 ] )

Функции для обработки html и специальных символов (самостоятельно)

• strip_tags — Strip HTML and PHP tags from a string
• addcslashes — Quote string with slashes in a C style
• addslashes — Quote string with slashes
• htmlentitydecode — Convert all HTML entities to their applicable characters
• htmlentities — Convert all applicable characters to HTML entities
• htmlspecialchars_decode — Convert special HTML entities back to characters
• htmlspecialchars — Convert special characters to HTML entities
• stripcslashes — Un-quote string quoted with addcslashes
• stripslashes — Un-quotes a quoted string
• nl2br — Inserts HTML line breaks before all newlines in a string
• gethtmltranslation_table — Returns the translation table used by htmlspecialchars and htmlentities

Остальной список (самостоятельно по желанию)

• bin2hex — Convert binary data into hexadecimal representation
• chunk_split — Split a string into smaller chunks
• convertcyrstring — Convert from one Cyrillic character set to another
• convert_uudecode — Decode a uuencoded string
• convert_uuencode — Uuencode a string
• count_chars — Return information about characters used in a string
• crypt — One-way string hashing
• crc32 — Calculates the crc32 polynomial of a string
• hebrev — Convert logical Hebrew text to visual text
• hebrevc — Convert logical Hebrew text to visual text with newline conversion
• hex2bin — Decodes a hexadecimally encoded binary string
• levenshtein — Calculate Levenshtein distance between two strings
• localeconv — Get numeric formatting information
• money_format — Formats a number as a currency string
• metaphone — Calculate the metaphone key of a string
• nl_langinfo — Query language and locale information
• number_format — Format a number with grouped thousands
• parse_str — Parses the string into variables
• quotedprintabledecode — Convert a quoted-printable string to an 8 bit string
• quotedprintableencode — Convert a 8 bit string to a quoted-printable string
• quotemeta — Quote meta characters
• setlocale — Set locale information
• similar_text — Calculate the similarity between two strings
• soundex — Calculate the soundex key of a string
• strireplace — Case-insensitive version of strreplace.
• str_pad — Pad a string to a certain length with another string
• str_repeat — Repeat a string
• str_replace — Replace all occurrences of the search string with the replacement string
• str_rot13 — Perform the rot13 transform on a string
• strwordcount — Return information about words used in a string
• strcasecmp — Binary safe case-insensitive string comparison
• strcmp — Binary safe string comparison
• strcoll — Locale based string comparison
• strcspn — Find length of initial segment not matching mask
• str_getcsv — Parse a CSV string into an array
• stripos — Find the position of the first occurrence of a case-insensitive substring in a string
• stristr — Case-insensitive strstr
• strnatcasecmp — Case insensitive string comparisons using a "natural order" algorithm
• strnatcmp — String comparisons using a "natural order" algorithm
• strncasecmp — Binary safe case-insensitive string comparison of the first n characters
• strncmp — Binary safe string comparison of the first n characters
• strpbrk — Search a string for any of a set of characters
• strripos — Find the position of the last occurrence of a case-insensitive substring in a string
• strrpos — Find the position of the last occurrence of a substring in a string
• strspn — Finds the length of the initial segment of a string consisting entirely of characters contained within a given mask.
• substr_compare — Binary safe comparison of two strings from an offset, up to length characters
• wordwrap — Wraps a string to a given number of characters