Java Arrays Java
This example shows how to merge two arrays into a new array. We can also append or prepend new elements using our
merge method.
package com.logicbig.example;
import java.lang.reflect.Array;
import java.util.Arrays;
public class ArrayMerge {
public static <T> T[] merge(T[] a, T[] b) {
int aLen = a.length;
int bLen = b.length;
@SuppressWarnings("unchecked")
T[] c = (T[]) Array.newInstance(a.getClass().getComponentType(), aLen + bLen);
System.arraycopy(a, 0, c, 0, aLen);
System.arraycopy(b, 0, c, aLen, bLen);
return c;
}
public static <T> T[] append(T[] a, T... b) {
return merge(a, b);
}
public static <T> T[] prepend(T[] a, T... b) {
return merge(b, a);
}
public static void main(String[] args) {
Integer[] ints1 = {1, 2, 3};
Integer[] ints2 = {5, 6, 7};
//merging
Integer[] merged = merge(ints1, ints2);
System.out.println(Arrays.toString(merged));
//appending
Integer[] append = append(ints1, 10, 11, 12);
System.out.println(Arrays.toString(append));
//prepending
Integer[] prepend = prepend(ints1, -3, -2, -1);
System.out.println(Arrays.toString(prepend));
}
}
[1, 2, 3, 5, 6, 7] [1, 2, 3, 10, 11, 12] [-3, -2, -1, 1, 2, 3]
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