$isupper

Tests if the letters in a character string are uppercase.

$isupper(string)

string

a character string or an expression that evaluates to a character string

1-character binary string. Evaluates to 1 ($True) if string meets the validation test; otherwise, evaluates to 0 ($False).

This function tests if a particular character string is uppercase, i.e., contains no lowercase letters.

$isupper("aBC")

Evaluates to $False.

$isupper(43)

Evaluates to $True.