IntlChar::isdefined

(PHP 7)

IntlChar::isdefined — Check whether the code point is defined

public static bool IntlChar::isdefined ( mixed $codepoint )

Determines whether the specified code point is "defined", which usually means that it is assigned a character.

TRUE for general categories other than "Cn" (other, not assigned).

Note:

Note that non-character code points (e.g., U+FDD0) are not "defined" (they are Cn), but surrogate code points are "defined" (Cs).

codepoint: The integer codepoint value (e.g. 0x2603 for U+2603 SNOWMAN), or the character encoded as a UTF-8 string (e.g. "\u{2603}")

Returns TRUE if codepoint is a defined character, FALSE if not.

Example #1 Testing different code points

  <?php
var_dump ( IntlChar :: isdefined ( "A" ));
 var_dump ( IntlChar :: isdefined ( " " ));
 var_dump ( IntlChar :: isdefined ( "\u{FDD0}" ));
 ?>

以上例程会输出：

bool(true)
bool(true)
bool(false)

IntlChar::isdigit() - Check if code point is a digit character
IntlChar::isalpha() - Check if code point is a letter character
IntlChar::isalnum() - Check if code point is an alphanumeric character
IntlChar::isupper() - Check if code point has the general category "Lu" (uppercase letter)
IntlChar::islower() - Check if code point is a lowercase letter
IntlChar::istitle() - Check if code point is a titlecase letter