(PHP 7, PHP 8)
IntlChar::isupper — Check if code point has the general category "Lu" (uppercase letter)
Determines whether the specified code point has the general category "Lu" (uppercase letter).
注意:
This misses some characters that are also uppercase but have a different general category value. In order to include those, use IntlChar::isUUppercase().
示例 #1 Testing different code points
<?php
var_dump(IntlChar::isupper("A"));
var_dump(IntlChar::isupper("a"));
var_dump(IntlChar::isupper("Φ"));
var_dump(IntlChar::isupper("φ"));
var_dump(IntlChar::isupper("1"));
?>以上示例会输出：
bool(true) bool(false) bool(true) bool(false) bool(false)
IntlChar::PROPERTY_UPPERCASE