# This:
# my $x="ex";

# Becomes:
my $x= 'ex'; # ... since there are no variables to interpolate

# This is wrong:
# my $foo = '/foo/$bar/baz'; # $bar is a variable and does not get interpolated
                             # instead, it's literally the string '$bar'

# It must be written with the double-quotes to interpolate:
# my $foo = "/foo/$bar/baz";