System.out.println ("\"\"\\\\\"\"");

Question

Why does this string print only ""\\""? Does the backslash do something to the string? Please explain the function of the backslash. All I know is that it is the escape character, but I don't understand why it does this to strings.

FYI the fact that you are using BlueJ is not actually relevant. — Manos Nikolaidis, Sep 20 '15 at 13:31
@ManosNikolaidis Sorry. I thought it'd be useful info. I will edit it out. — TheUnicornMaster, Sep 20 '15 at 13:31

Manos Nikolaidis · Accepted Answer · 2015-09-20T15:39:58.293

3

The backslash '\' can be used in a String to add characters that would otherwise be illegal (e.g. " and ') or have another meaning (e.g. t, b, n, r, f and \). for your particular example :

The first 2 backslashes are escaping the double quotes. So \"\" is printed as ""
The next backslashes are escaping the backslashes that immediately follow so \\\\ is printed as \\
The last 2 backslashes behave as the first 2 escaping the quotes so \"\" is printed as ""

edited Sep 20 '15 at 15:39

answered Sep 20 '15 at 13:28

Manos Nikolaidis

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I would add for beginners: You have to use a backlash \ if you wan't to treat an special character as a String and it is the reason why it happens. – Francisco Romero Sep 20 '15 at 13:32
Agreed. Except '/' is a slash and '\' a backslash. – Manos Nikolaidis Sep 20 '15 at 13:35
Of course. Totally agree. A silly mistake :S – Francisco Romero Sep 20 '15 at 13:36
@ManosNikolaidis Thanks for the link. I actually read it before I posted this question. But it does not tell what a backslash does to a string. Maybe I missed something though – TheUnicornMaster Sep 20 '15 at 13:42
@ManosNikolaidis Sorry. I meant the top part of the question where it said it was a duplicate. Marcus's answer is fine. – TheUnicornMaster Sep 20 '15 at 13:50

score 2 · Answer 2 · answered Sep 20 '15 at 13:29

The Backslash is the escape character, used to encode special things like " in your string (which you normally couldn't use, because they'd mark the end of a string). You should read up on "String literals" in the official Java documentation or the book you read to learn Java.

System.out.println ("\"\"\\\\\"\"");

2 Answers2