Java: regular expression: difference between "\\/" and "/"

Question

Is there any difference between regular expressions x1 = "\\/" and x2 = "/"?

I could not find and strings s, such that s.split(x1) would not be equal to s.split(x2). (The same holds, when I replace / by, e.g., a.) I am on Windows.

You will have a difference when you use reserved characters like '.' '\', etc — Cédric O., Oct 26 '16 at 11:32
try to print the content of `"\\/`, `"/"` and you might find the difference yourself — SomeJavaGuy, Oct 26 '16 at 11:32
You ask what the difference between `\/` and `/` patterns are. None as you can see for yourself at http://regex101.com. — Wiktor Stribiżew, Oct 26 '16 at 11:37
@KevinEsche This is precisely the reason why I am asking this question, since the first one gives `\/`, while the second one `/`. However, if I split "a\\/b", I get `[a\, b]` in both cases, which I find weird. — Antoine, Oct 26 '16 at 11:37
Reopened as the duplicate was inappropriate. The topic there are regexes in general and, even after going through that huge pile of text, I still couldn't find an explicit statement that answers this question. — Marko Topolnik, Oct 26 '16 at 11:57

score 0 · Accepted Answer · edited Oct 26 '16 at 12:07

0

No, there is no difference. x1 is actually \/ but / doesn't need backslash escaping (unlike \) and it's not a special string (tab, new line etc.)

String t = "th/is i/s a /test \\/t";
String r1 = "/";
String r2 = "\\/";
String[] t1 = t.split(r1);
for (int i = 0; i < t1.length; i++) {
    System.out.println(t1[i]);
}

OR

String[] t2 = t.split(r2);
for (int i = 0; i < t2.length; i++) {
    System.out.println(t2[i]);
}

these two produce the same output.

edited Oct 26 '16 at 12:07

Alan Moore

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answered Oct 26 '16 at 11:31

ItamarG3

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i would think that `\/` ia an invalid regex? you have to escape a special char? – Sharon Ben Asher Oct 26 '16 at 11:33
it's not regex. it's a simple text (*not* java text) – ItamarG3 Oct 26 '16 at 11:34
the original question is explicitly about the regex string – Sharon Ben Asher Oct 26 '16 at 11:35
You misunderstand my response... `\/` is what the regex would look like if one didn't need to escape a special char... – ItamarG3 Oct 26 '16 at 11:36
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@sharonbn "A backslash may be used prior to a non-alphabetic character regardless of whether that character is part of an unescaped construct." – Andy Turner Oct 26 '16 at 11:37

Java: regular expression: difference between "\\/" and "/"

1 Answers1