The backslash (\
) is an escape character in Javascript (along with a lot of other C-like languages). This means that when Javascript encounters a backslash, it tries to escape the following character. For instance, \n
is a newline character (rather than a backslash followed by the letter n).
In order to output a literal backslash, you need to escape it. That means \\
will output a single backslash (and \\\\
will output two, and so on). The reason "aa ///\"
doesn’t work is because the backslash escapes the "
(which will print a literal quote), and thus your string is not properly terminated. Similarly, "aa ///\\\"
won’t work, because the last backslash again escapes the quote.
Just remember, for each backslash you want to output, you need to give Javascript two.