Only ascii 32 thru 126 (inclusive) are considered printable. Tab (ascii 7), carriage return (ascii 13), linefeed (ascii 10) etc may produce output but are not considered printable.
ctype_print
(PHP 4 >= 4.0.4, PHP 5, PHP 7)
ctype_print — Check for printable character(s)
Opis
ctype_print
( string
$text
) : bool
Checks if all of the characters in the provided string,
text, are printable.
Parametry
-
text -
The tested string.
Zwracane wartości
Returns TRUE if every character in text
will actually create output (including blanks). Returns FALSE if
text contains control characters or characters
that do not have any output or control function at all.
Przykłady
Przykład #1 A ctype_print() example
<?php
$strings = array('string1' => "asdf\n\r\t", 'string2' => 'arf12', 'string3' => 'LKA#@%.54');
foreach ($strings as $name => $testcase) {
if (ctype_print($testcase)) {
echo "The string '$name' consists of all printable characters.\n";
} else {
echo "The string '$name' does not consist of all printable characters.\n";
}
}
?>
Powyższy przykład wyświetli:
The string 'string1' does not consist of all printable characters. The string 'string2' consists of all printable characters. The string 'string3' consists of all printable characters.
Notatki
Informacja:
Jeśli podana zostanie zmienna typu integer o wartości z zakresu -128 i 255 włącznie, jest ona interpretowana jako wartość ASCII dla pojedynczego znaku (do ujemnych wartości dodaje się liczbę 256 aby przejść do zakresu wartości występujących w rozszerzonej tablicy ASCII). Każda inna zmienna całkowita jest interpretowana jako ciąg znakowy zwierający cyfry dziesiętne liczby całkowitej.
Zobacz też:
- ctype_cntrl() - Check for control character(s)
- ctype_graph() - Check for any printable character(s) except space
- ctype_punct() - Check for any printable character which is not whitespace or an alphanumeric character
add a note
User Contributed Notes 2 notes
Anonymous ¶
11 years ago
ClayDragon ¶
5 years ago
As mentioned above, only ASCII characters from 32 to 126 are considered printable, all others, including UTF-8 encoded characters are always considered unprintable, no matter what your locale settings are. Therefore, e.g. German "ä", the Euro sign "€" or the British pound symbol "£" will never be printable. If you need to check any characters for "printability" beyond the standard ASCII range, use a regular expression or write a specific function yourself.
See also this discussion: https://grokbase.com/t/php/php-i18n/102tkqe6rk/ctype-print-returns-false-for-british-pound-symbol-and-non-ascii-symbols
