Converts alphabetic characters to upper case.
|source||any value, or an expression that yields any value|
Character string, in which all letters are uppercase.
$toupper returns a character string in which all letters are upper case. If source is not of a character data type, it is converted to a character data type before the function is applied.
$toupper(“the QUICK BROWN fox is 30 years oLD”)
Evaluates to “THE QUICK BROWN FOX IS 30 YEARS OLD”.