' \ '-Invalid character constant?

Question

I need to do this:

while (result2.charAt(j) != '\'){
    
}

I get an error saying: Invalid character constant.

Why? And how can I get over it?

score 9 · Answer 1 · answered May 14 '11 at 14:15

9

The backslash is a special character and it needs to be escaped with another backslash. Like this:

while (result2.charAt(j)!='\\'){

}

answered May 14 '11 at 14:15

Asaph

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Will it be considered as '\'? – Unknown user May 14 '11 at 14:20
1

@Unknown user - yes, it will. – Oded May 14 '11 at 14:22
Thank you very much guys. How can I get these kind of information without bother you here? :-) does java have something somewhere for these stuff? – Unknown user May 14 '11 at 14:23
@Unknown You can go to the Java Tutorials. For example in http://download.oracle.com/javase/tutorial/java/data/characters.html you can see what you were looking for. – Marcelo May 14 '11 at 14:53

score 3 · Answer 2 · answered May 14 '11 at 14:16

3

Use '\\'. It's because backslash is used in escape sequence like '\n'. With a single \ the compiler have no way to know.

answered May 14 '11 at 14:16

taskinoor

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SquidScareMe · Answer 3 · 2011-05-14T14:26:55.363

2

Looks like you need to escape the backslash. Try

while (result2.charAt(j)!='\\'){

    }

edited May 14 '11 at 14:26

answered May 14 '11 at 14:15

SquidScareMe

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I want to compare it to a backslah. – Unknown user May 14 '11 at 14:15
@Uknown user: Yes. we understand. This is the solution. Try it. – Asaph May 14 '11 at 14:17
3

`charAt()` returns a `char`, not a `String`, so you cannot call `compareTo()` on it. So your second suggestion is broken. – Asaph May 14 '11 at 14:20
@Asaph. Whoops, thank you very much for catching my mistake. I removed the incorrect advice. – SquidScareMe May 14 '11 at 14:28

score 0 · Answer 4 · answered Dec 28 '12 at 12:51

I got this similar error in Eclipse for Android although for different situation, and I just figured out that in Java you cannot enclose a string (multi-character word) in single quotes. So you need to have like - "sampleword" strings enclosed in double quotes rather than single quote to get rid of such error thought I could just share it here for others to refer..

score 0 · Answer 5 · answered Jul 20 '15 at 19:48

0

Same error here, but using unicode character representation.

005C is backlash character. Need to escape it: "\u005C" .

Example:

str = str.replace("\\u005C", "'\\u005C'");

answered Jul 20 '15 at 19:48

live-love

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score 0 · Answer 6 · answered May 14 '11 at 14:16

0

You need to escape it I think,

So you need to do

while(results2.charAt(j)!='\\')
{
}

I think that's the solution I think

answered May 14 '11 at 14:16

score 0 · Answer 7 · answered May 14 '11 at 15:06

0

you need an extra character '\'

" " " == " \" "


" \ " == " \\ "

answered May 14 '11 at 15:06

Eng.Fouad

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' \ '-Invalid character constant?

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