How can I have a newline in a string in sh?

Question

This

STR=\"Hello\\nWorld\"
echo $STR

produces as output

Hello\\nWorld

instead of

Hello
Wo         


        

Answer 1

A $ right before single quotation marks '...\n...' as follows, however double quotation marks doesn't work.

$ echo $'Hello\nWorld'
Hello
World
$ echo $"Hello\nWorld"
Hello\nWorld