You should assign the result of uc(...) to another variable.

$name = "world";
$uc_name = uc($name);
print $uc_name,$/;
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if you want to change the case of the current variable, you could use tr.

$name = "world";
$name =~ tr/[a-z]/[A-Z]/;
print $name, $/;
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--
hiseldl
"Act better than you feel"