CODEWITHSUNDEEP
javaarraysjoin
Leo
Leo

Reputation: 659

java join elements in array

Suppose I have an int array:

intarray = [2,3,5,7,8,8,9,3...]

how to join the first 5 elements there or others?

for instance, I would have the numbers 23578 or 35788 or 57889...?

I'm trying to do it because I need to compare the numbers with each other

by the way, I'm still looking for great source that keep all docs about java language

Upvotes: 1

Views: 5653

Answers (4)

Ring
Ring

Reputation: 2309

StringUtils.join([1, 2, 3], null) = "123"

from apache commons-lang

Upvotes: 0

Achintya Jha
Achintya Jha

Reputation: 12843

public static void main(String[] args) {
    int[] intarray = new int[] { 2, 3, 5, 7, 8, 8, 9, 3 };

    for (int j = 0; j < intarray.length - 4; j++) {
        String s = "";
        for (int i = j; i < j + 5; i++) {
            s = s + String.valueOf(intarray[i]);
        }
        int value = Integer.parseInt(s);
        System.out.println(value);
    }
}

Output:

23578
35788
57889
78893

Upvotes: 2

David Roussel
David Roussel

Reputation: 5916

If you want to use a library, and work at a higher level, try Guava.

    int[] ary = {7,4,1,2,5,8,9,3};
    Iterable<int[]> first5 = Iterables.limit(Lists.newArrayList(ary), 5);
    String joined = Joiner.on("").join(first5);

See Iterables.limit()

Upvotes: 1

Armen Tsirunyan
Armen Tsirunyan

Reputation: 133072

pseudocode:

    int frstNumber = 0;
    for i = 0 to 4
         firstNumber *= 10;
         firstNumber += array[i];

    nextNumber = firstNumber
    for i = 5 to end of array
         nextNumber = (nextNumber mod 10000) * 10 + array[i]

Upvotes: 2

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