String replace a Backslash

Question

How can I do a string replace of a back slash.

Input Source String:

sSource = "http://www.example.com\/value";

In the above String I want to replace "\/" with a "/";

Expected ouput after replace:

sSource = "http://www.example.com/value";

I get the Source String from a third party, therefore I have control over the format of the String.

This is what I have tried

Trial 1:

sSource.replaceAll("\\", "/");

Exception Unexpected internal error near index 1 \

Trial 2:

 sSource.replaceAll("\\/", "/");

No Exception, but does not do the required replace. Does not do anything.

Trial 3:

 sVideoURL.replace("\\", "/");

No Exception, but does not do the required replace. Does not do anything.

btw, you source cannot be `\/` if you declare it as a string literal. But I will assume it is coming from somewhere else. — Bozho, Apr 08 '11 at 14:27
In your example, you replace \ with nothing, not with /; there is already a forward slash. — user unknown, Apr 08 '11 at 14:28
possible duplicate of [Backslash problem with String.replaceAll](http://stackoverflow.com/questions/1701839/backslash-problem-with-string-replaceall) — McDowell, May 26 '11 at 08:38

score 55 · Accepted Answer · answered Apr 08 '11 at 14:20

sSource = sSource.replace("\\/", "/");

String is immutable - each method you invoke on it does not change its state. It returns a new instance holding the new state instead. So you have to assign the new value to a variable (it can be the same variable)
replaceAll(..) uses regex. You don't need that.

Paŭlo Ebermann · Answer 2 · 2020-02-05T20:33:46.097

Try replaceAll("\\\\", "") or replaceAll("\\\\/", "/").

The problem here is that a backslash is (1) an escape chararacter in Java string literals, and (2) an escape character in regular expressions – each of this uses need doubling the character, in effect needing 4 \ in row.

Of course, as Bozho said, you need to do something with the result (assign it to some variable) and not throw it away. And in this case the non-regex variant is better.

greydet · Answer 3 · 2011-04-08T14:29:17.663

14

Try

   sSource = sSource.replaceAll("\\\\", "");

Edit : Ok even in stackoverflow there is backslash escape... You need to have four backslashes in your replaceAll first String argument...

The reason of this is because backslash is considered as an escape character for special characters (like \n for instance).
Moreover replaceAll first arg is a regular expression that also use backslash as escape sequence.
So for the regular expression you need to pass 2 backslash. To pass those two backslashes by a java String to the replaceAll, you also need to escape both backslashes.
That drives you to have four backslashes for your expression! That's the beauty of regex in java ;)

edited Apr 08 '11 at 14:29

answered Apr 08 '11 at 14:20

greydet

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Won't work. use replace() instead of replaceAll() or use four backslashes – Sean Patrick Floyd Apr 08 '11 at 14:23
For stackoverflow syntax, use `` or four spaces in front to disable parsing (and format it as code). – Paŭlo Ebermann Apr 08 '11 at 14:25
1

Yep I didn't see that my backslashes were not escaped :) I edited my answer – greydet Apr 08 '11 at 14:30

score 7 · Answer 4 · answered Apr 08 '11 at 14:31

7

s.replaceAll ("\\\\", "");

You need to mask a backslash in your source, and for regex, you need to mask it again, so for every backslash you need two, which ends in 4.

But

s = "http://www.example.com\\/value";

needs two backslashes in source as well.

answered Apr 08 '11 at 14:31

user unknown

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score 5 · Answer 5 · edited Sep 02 '15 at 14:33

5

This will replace backslashes with forward slashes in the string:

source = source.replace('\\','/');

edited Sep 02 '15 at 14:33

Lőrincz Péter

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answered Aug 06 '14 at 20:42

Dale

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Plain and simple :D and no regexp ;) – FibreFoX May 11 '16 at 08:24

score 2 · Answer 6 · answered Apr 08 '11 at 14:24

2

you have to do

sSource.replaceAll("\\\\/", "/");

because the backshlash should be escaped twice one for string in source one in regular expression

answered Apr 08 '11 at 14:24

Xavier Combelle

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score 1 · Answer 7 · edited Mar 03 '17 at 10:02

1

To Replace backslash at particular location:

if ((stringValue.contains("\\"))&&(stringValue.indexOf("\\", location-1)==(location-1))) {
    stringValue=stringValue.substring(0,location-1);
}

edited Mar 03 '17 at 10:02

Manfred Radlwimmer

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answered Mar 01 '17 at 10:11

suyog talekar

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score 0 · Answer 8 · answered Oct 15 '14 at 11:08

0

 sSource = StringUtils.replace(sSource, "\\/", "/")

answered Oct 15 '14 at 11:08

Gustavo

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Could you explain what was wrong with OP's code and why this one is better to use? – vyegorov Oct 15 '14 at 11:29

String replace a Backslash

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