ctype_upper

Check for uppercase character(s)

ctype_upper ( mixed $text ) : bool

text

The tested string.

Note: If an integer between -128 and 255 inclusive is provided, it is interpreted as the ASCII value of a single character (negative values have 256 added in order to allow characters in the Extended ASCII range). Any other integer is interpreted as a string containing the decimal digits of the integer.

Returns TRUE if every character in text is an uppercase letter in the current locale.

<?

$text = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

$return = ctype_upper($text);

var_export($return);

?>

true

<?

for ($i = 0; $i <= 255; ++$i)
{
    $return = ctype_upper($i);

    if ($return)
    {
        $character = chr($i);

        echo "$i: $character\n";
    }
}

?>

65: A
66: B
67: C
68: D
69: E
70: F
71: G
72: H
73: I
74: J
75: K
76: L
77: M
78: N
79: O
80: P
81: Q
82: R
83: S
84: T
85: U
86: V
87: W
88: X
89: Y
90: Z

PHP