(PHP 7, PHP 8)
IntlChar::isdefined — Check whether the code point is defined
$codepoint): ?boolDetermines 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).
注意:
Note that non-character code points (e.g., U+FDD0) are not "defined" (they are Cn), but surrogate code points are "defined" (Cs).
codepointThe int 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. Returns null on failure.
示例 #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)