udebella

// Enum version
public enum EnumSingleton {
    INSTANCE;
}

// Classic version
public class ClassicSingleton {
    private static ClassicSingleton instance;
    
    private ClassicSingleton() {}

udebella

import java.util.Arrays;
import java.util.stream.IntStream;

public class MergeArray {
    public int[] mergeArrays(int[] array1, int[] array2) {
        return IntStream.concat(Arrays.stream(array1), Arrays.stream(array2))
                .sorted()
                .toArray();
    }
}