A function I wrote last night was fairly flexible in terms of detecting whitespace, and even took into account the pesky non-breaking spaces / zero-width spaces further up the Unicode alphabet.
The benefit here was being able to isolate and identify specific Unicode indices based on their subrange.
<?php
// Returns TRUE if the ASCII value of $string matches a registered whitespace character.
// * This includes non-breaking spaces, zero-width spaces, and any unicode values below 32.
// * $string: Character to identify. If string extends past one character, the value
// is truncated and only the initial character is examined.
function is_whitespace($string){
// Return FALSE if passed an empty string.
if($string == "") return FALSE;
$char = ord($string);
// Control Characters
if($char < 33) return TRUE;
if($char > 8191 && $char < 8208) return TRUE;
if($char > 8231 && $char < 8240) return TRUE;
// Additional Characters
switch($char){
case 160: // Non-Breaking Space
case 8287: // Medium Mathematical Space
return TRUE;
break;
}
return FALSE;
}
?>
ctype_space
(PHP 4 >= 4.0.4, PHP 5, PHP 7)
ctype_space — Check for whitespace character(s)
Opis
ctype_space
( string
$text
) : bool
Checks if all of the characters in the provided string,
text, creates whitespace.
Parametry
-
text -
The tested string.
Zwracane wartości
Returns TRUE if every character in text
creates some sort of white space, FALSE otherwise. Besides the
blank character this also includes tab, vertical tab, line feed,
carriage return and form feed characters.
Przykłady
Przykład #1 A ctype_space() example
<?php
$strings = array(
'string1' => "\n\r\t",
'string2' => "\narf12",
'string3' => '\n\r\t' // note the single quotes
);
foreach ($strings as $name => $testcase) {
if (ctype_space($testcase)) {
echo "The string '$name' consists of whitespace characters only.\n";
} else {
echo "The string '$name' contains non-whitespace characters.\n";
}
}
?>
Powyższy przykład wyświetli:
The string 'string1' consists of whitespace characters only. The string 'string2' contains non-whitespace characters. The string 'string3' contains non-whitespace 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
gardnerjohng at hotmail dot com ¶
14 years ago
vlabots at gmail dot com ¶
9 years ago
thanks to gardnerjohng, but a had some problems with non-breaking spaces in this function.
I added 2 more cases for this:
case 0xC2
case 0xA0
After this modification non-breaking spaces in my test code were successfully detected.
