Underscores in the string will result in false, so you have to remove them first.
ctype_upper
(PHP 4 >= 4.0.4, PHP 5, PHP 7)
ctype_upper — Check for uppercase character(s)
Description
ctype_upper
( string
$text
) : bool
Checks if all of the characters in the provided string,
text, are uppercase characters.
Parameters
-
text -
The tested string.
Return Values
Returns TRUE if every character in text is
an uppercase letter in the current locale.
Examples
Example #1 A ctype_upper() example (using the default locale)
<?php
$strings = array('AKLWC139', 'LMNSDO', 'akwSKWsm');
foreach ($strings as $testcase) {
if (ctype_upper($testcase)) {
echo "The string $testcase consists of all uppercase letters.\n";
} else {
echo "The string $testcase does not consist of all uppercase letters.\n";
}
}
?>
The above example will output:
The string AKLWC139 does not consist of all uppercase letters. The string LMNSDO consists of all uppercase letters. The string akwSKWsm does not consist of all uppercase letters.
Notes
Note:
If an integer between -128 and 255 inclusive is provided, it is interpreted as the ASCII value of a single character (negative values have 256 added in order to allow characters in the Extended ASCII range). Any other integer is interpreted as a string containing the decimal digits of the integer.
See Also
- ctype_alpha() - Check for alphabetic character(s)
- ctype_lower() - Check for lowercase character(s)
- setlocale() - Set locale information
add a note
User Contributed Notes 2 notes
chris at theothernews dot co dot nz ¶
5 years ago
Anonymous ¶
3 years ago
// after screwing around with function.ctype-upper
// I found this simple solution
if (strtolower($string) != $string)// its so simple!
{
echo "uppercase letters found in $string";
}
source: http://stackoverflow.com/questions/4426327/how-to-detect-if-string-contains-1-uppercase-letter-in-php
