How to concat two char arrays in java?

Question

How to concatenate two char arrays in java ?

char info[]=new char[10];
char data[]=new char[10];
char result[]=new char[40];

I need to concatenate info and data, and store the concatenation in result:

result=info+data;

How to do this?

http://stackoverflow.com/questions/80476/how-to-concatenate-two-arrays-in-java — Peter Jaloveczki, Jun 12 '13 at 08:32
http://docs.oracle.com/javase/6/docs/api/java/nio/CharBuffer.html — Fildor, Jun 12 '13 at 08:32

score 9 · Answer 1 · answered Jun 12 '13 at 08:33

9

It depends I guess. The simpler approach would be just to convert the char arrays to a String and concaternate the Strings.

A better approach would be to use StringBuilder

char info[] = new char[10];
char data[] = new char[10];


// Assuming you've filled the char arrays...

StringBuilder sb = new StringBuilder(64);
sb.append(info);
sb.append(data);

char result[] = sb.toString().toCharArray();

answered Jun 12 '13 at 08:33

MadProgrammer

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If he wants the output as a string that is a nice approach. – assylias Jun 12 '13 at 08:35
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I don't think you want to append `result`. He says he wants `result = info + data`. In your case, the last line should be `result = sb.toString().toCharArray();` – Aleks G Jun 12 '13 at 08:36
@assylias Yeah I thought that to, I also thought that `sb.toString().toCharArray()` to get the character array back. This of course assumes the OP wants to only use `char` arrays ;) – MadProgrammer Jun 12 '13 at 08:36
@AleksG Ah, that's true, missed that. Thanks – MadProgrammer Jun 12 '13 at 08:37
4

Love down votes without comment, makes me all warm and fuzzy inside :P – MadProgrammer Jun 12 '13 at 08:39
Just gave you a upvote even though it's old and full of solutions.. – HoKy22 Mar 15 '14 at 05:09

score 5 · Answer 2 · answered Jun 12 '13 at 08:36

5

try this

char result[] = new char[info.length + data.length];
System.arraycopy(info, 0, result, 0, info.length);
System.arraycopy(data, 0, result, info.length, data.length);

answered Jun 12 '13 at 08:36

Evgeniy Dorofeev

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score 2 · Answer 3 · edited Jun 12 '13 at 09:48

2

Just found one-line solution from the old Apache Commons Lang library: ArrayUtils addAll()

edited Jun 12 '13 at 09:48

Andreas

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answered Jun 12 '13 at 09:27

Developer

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How to concat two char arrays in java?

3 Answers3

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