Java Arrays - How to return array in java from method?

1, Overview

In this tutorial, We'll learn how to return an array from a method in java.

If you are new to java programming, please refer to the article on How to initialize an array in java?

Thump rules:

• A method can return an array that is referencing another array.
• The return type of method must be declared as the correct array type.

2. Java Return Array from Method - int[] primitive array

In the below example, getNumbers() method returns an integer primitive type array.

Example 1:

package com.javaprogramto.arrays.returns;

import java.util.Arrays;

public class ArrayReturnExample1 {

	public static void main(String[] args) {

		int[] first5Numbers = getNumbers();

		System.out.println("Array returned from method : " + Arrays.toString(first5Numbers));

	}

	// returning an array from method
	public static int[] getNumbers() {

		int[] numbers = { 1, 2, 3, 4, 5 };

		return numbers;
	}
}

Output:

Array returned from method : [1, 2, 3, 4, 5]

3. Java Return Array - double[] primitive & wrapper array

Below example returns a double[] array from the method.

Example 2:

package com.javaprogramto.arrays.returns;

import java.util.Arrays;

public class ArrayReturnExample2 {

	public static void main(String[] args) {

		double[] first5Numbers = getDoublePRimitive(5);

		System.out.println("Double primitive Array returned from method : " + Arrays.toString(first5Numbers));

		Double[] first6Numbers = getDoubleWrapper(5);

		System.out.println("Double wrapper Array returned from method : " + Arrays.toString(first6Numbers));

	}

	// returning double primitive array from method
	public static double[] getDoublePRimitive(int size) {

		double[] numbers = new double[size];

		for (int i = 0; i < size; i++) {
			numbers[i] = i + 1;
		}

		return numbers;
	}

	// returning Double wrapper array from method
	public static Double[] getDoubleWrapper(int size) {

		Double[] numbers = new Double[size];

		for (int i = 0; i < size; i++) {
			numbers[i] = Double.valueOf(i + 1);
		}

		return numbers;
	}
}

Output:

Double primitive Array returned from method : [1.0, 2.0, 3.0, 4.0, 5.0]
Double wrapper Array returned from method : [1.0, 2.0, 3.0, 4.0, 5.0, 6.0]

4. Java Return Array - Custom Objects

Example 3:

package com.javaprogramto.arrays.returns;

import java.util.Arrays;

public class ArrayReturnExample3 {

	public static void main(String[] args) {

		CustomObject[] objects = getObjects();

		System.out.println("Returned custom objects - " + Arrays.toString(objects));

	}

	// returning custom objects array from method
	public static CustomObject[] getObjects() {
		return new CustomObject[] { new CustomObject("Ram", 30), new CustomObject("Sita", 20) };

	}
}

class CustomObject {
	public String name;
	public int age;

	public CustomObject(String name, int age) {
		this.age = age;
		this.name = name;
	}

	@Override
	public String toString() {
		return "CustomObject [name=" + name + ", age=" + age + "]";
	}

}

Output:

Returned custom objects - [CustomObject [name=Ram, age=30], CustomObject [name=Sita, age=20]]

5. Java Return Array - Multidimensional Array

Example 4:

package com.javaprogramto.arrays.returns;

import java.util.Arrays;

public class ArrayReturnExample4 {

	public static void main(String[] args) {

		int[][] multiArray = getMultiArray();

		System.out.println("Returned Multi dimentional array values : ");
		for(int[] a : multiArray) {
			System.out.println( Arrays.toString(a));
		}

	}

	// returning multi dimens
	public static int[][] getMultiArray() {

		int[][] multi = { { 1, 2, 3 }, { 4, 5, 6 } };
		return multi;

	}
}

Output:

Returned Multi dimentional array values : 
[1, 2, 3]
[4, 5, 6]

6. Conclusion

In this article, we've seen how to return different types of arrays from a method in java.

GitHub

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