You are viewing the version of this documentation from Perl blead. This is the main development branch of Perl. (git commit e52946b01aa0f6f27808f344cf8d9b504831c51c)
uc EXPR
uc

Returns an uppercased version of EXPR. If EXPR is omitted, uses $_.

my $str = uc("Perl is GREAT"); # "PERL IS GREAT"

This function behaves the same way under various pragmas, such as in a locale, as lc does.

If you want titlecase mapping on initial letters see ucfirst instead.

Note: This is the internal function implementing the \U escape in double-quoted strings.

my $str = "Perl is \Ugreat\E"; # "Perl is GREAT"