CODEWITHSUNDEEP
javaconcatenationarrays
VictorGram
VictorGram

Reputation: 2661

How to concat two string arrays in Java

I am using JDK 1.7 and Eclipse and trying to concat two string arrays:

String [] a1 = { "a12", "b12" };
String [] a2 = { "c12", "d23", "ewe", "fdfsd" };

I have tried 

String[] both = ObjectArrays.concat(a1,a2,String.class);

imported 

import com.google.common.collect.ObjectArrays;

getting Error:

can not resolve "import com.google.common.collect.ObjectArrays"

Can anyone help? I am using Maven to build the project.

Upvotes: 6

Views: 12495

Answers (7)

Alisa
Alisa

Reputation: 3072

I found that the easiest way to avoid all those startingIndex and endingIndex parameters in arrayCopy() and copyOf() is to write a specific method (which is straightforward):

public static String[] concatTwoStringArrays(String[] s1, String[] s2){
    String[] result = new String[s1.length+s2.length];
    int i;
    for (i=0; i<s1.length; i++)
        result[i] = s1[i];
    int tempIndex =s1.length; 
    for (i=0; i<s2.length; i++)
        result[tempIndex+i] = s2[i];
    return result;
}//concatTwoStringArrays().

So here's the usage of concatTwoStringArrays() method:

String[] s3 = concatTwoStringArrays(s1, s2);

Upvotes: 0

DavideBar
DavideBar

Reputation: 75

Why don't you do a for loop and store all the elements to one String and then use .split ?

String result = null;
for(String aux : a1){
   final += aux + ";";
}

for(String aux1 : a2){
   final += aux1 + ";";
}
String[] finalArray= result.split(";");

I made this out of the paper, but I'm almost sure it will work ;)

Upvotes: 0

Denis Kulagin
Denis Kulagin

Reputation: 8906

Add right Maven dependency to your POM:

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.3.2</version>
</dependency>

Upvotes: 1

user3567218
user3567218

Reputation: 11

Download common.codec-1.9.jar (Download zip and extract you will find the jar file) then if you are using an IDE like

Eclipse:

1.Right-click your Project.

2.Select Properties.

3.On the left-hand side click java build path.

4.Under Libraries Tab, click Add External Jars button.

5.Choose the downloaded file and click ok

Netbeans :

1.Right-click your Project.

2.Select Properties.

3.On the left-hand side click Libraries.

4.Under Compile tab - click Add Jar/Folder button.

Upvotes: 1

Evgeniy Dorofeev
Evgeniy Dorofeev

Reputation: 136012

Alternatevely you can do it this way

    String[] a3 = Arrays.copyOf(a1, a1.length + a2.length);
    System.arraycopy(a2, 0, a3, a1.length, a2.length);

Upvotes: 4

mttdbrd
mttdbrd

Reputation: 1831

This code should work. Not as pretty as the ArrayUtils.addAll(), but functional. You also can avoid having to import anything and you won't need to ship a 3rd party library for just one function.

String[] both = new String[a1.length + a2.length];
System.arraycopy(a1,0,both,0, a1.length);
System.arraycopy(a2,0,both,a1.length + 1, a2.length);

Upvotes: 3

Sotirios Delimanolis
Sotirios Delimanolis

Reputation: 279960

It's not enough to import a type. You need to actually provide that type on the classpath when compiling your code.

It seems 

can not resolve "import org.apache.commons.lang3.ArrayUtil"

like you haven't provided the jar containing the type above on your classpath.

Upvotes: 7

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