(PHP 7)
IntlChar::istitle — Check if code point is a titlecase letter
Determines whether the specified code point is a titlecase letter.
   TRUE for general category "Lt" (titlecase letter).
  
codepointThe 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 titlecase letter, FALSE if not.
  
Example #1 Testing different code points
<?php
var_dump(IntlChar::istitle("A"));
var_dump(IntlChar::istitle("a"));
var_dump(IntlChar::istitle("Φ"));
var_dump(IntlChar::istitle("φ"));
var_dump(IntlChar::istitle("1"));
?>
以上例程会输出:
bool(false) bool(true) bool(false) bool(true) bool(false)