[JAVA-616] core-java-arrays-multidimensional
* Creation * Moved code from https://www.baeldung.com/java-jagged-arrays * Moved code from https://www.baeldung.com/java-loop-diagonal-array
This commit is contained in:
dupirefr
@@ -6,6 +6,5 @@ This module contains articles about Java arrays
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- [How to Copy an Array in Java](https://www.baeldung.com/java-array-copy)
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- [Check if a Java Array Contains a Value](https://www.baeldung.com/java-array-contains-value)
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- [Initializing Arrays in Java](https://www.baeldung.com/java-initialize-array)
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- [Multi-Dimensional Arrays In Java](https://www.baeldung.com/java-jagged-arrays)
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- [Find Sum and Average in a Java Array](https://www.baeldung.com/java-array-sum-average)
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- [[More -->]](/core-java-modules/core-java-arrays-2)
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@@ -1,83 +0,0 @@
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package com.baeldung.array;
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import java.util.Arrays;
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import java.util.Scanner;
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public class MultiDimensionalArray {
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int[][] shortHandFormInitialization() {
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int[][] multiDimensionalArray = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
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return multiDimensionalArray;
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}
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int[][] declarationAndThenInitialization() {
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int[][] multiDimensionalArray = new int[3][];
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multiDimensionalArray[0] = new int[] { 1, 2 };
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multiDimensionalArray[1] = new int[] { 3, 4, 5 };
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multiDimensionalArray[2] = new int[] { 6, 7, 8, 9 };
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return multiDimensionalArray;
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}
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int[][] declarationAndThenInitializationUsingUserInputs() {
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int[][] multiDimensionalArray = new int[3][];
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multiDimensionalArray[0] = new int[2];
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multiDimensionalArray[1] = new int[3];
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multiDimensionalArray[2] = new int[4];
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initializeElements(multiDimensionalArray);
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return multiDimensionalArray;
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}
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void initializeElements(int[][] multiDimensionalArray) {
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Scanner sc = new Scanner(System.in);
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for (int outer = 0; outer < multiDimensionalArray.length; outer++) {
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for (int inner = 0; inner < multiDimensionalArray[outer].length; inner++) {
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multiDimensionalArray[outer][inner] = sc.nextInt();
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}
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}
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}
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void initialize2DArray(int[][] multiDimensionalArray) {
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for (int[] array : multiDimensionalArray) {
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Arrays.fill(array, 7);
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}
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}
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void printElements(int[][] multiDimensionalArray) {
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for (int index = 0; index < multiDimensionalArray.length; index++) {
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System.out.println(Arrays.toString(multiDimensionalArray[index]));
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}
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}
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int[] getElementAtGivenIndex(int[][] multiDimensionalArray, int index) {
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return multiDimensionalArray[index];
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}
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int[] findLengthOfElements(int[][] multiDimensionalArray) {
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int[] arrayOfLengths = new int[multiDimensionalArray.length];
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for (int i = 0; i < multiDimensionalArray.length; i++) {
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arrayOfLengths[i] = multiDimensionalArray[i].length;
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}
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return arrayOfLengths;
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}
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Integer[] findLengthOfElements(Integer[][] multiDimensionalArray) {
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return Arrays.stream(multiDimensionalArray)
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.map(array -> array.length)
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.toArray(Integer[]::new);
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}
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int[][] copy2DArray(int[][] arrayOfArrays) {
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int[][] copied2DArray = new int[arrayOfArrays.length][];
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for (int i = 0; i < arrayOfArrays.length; i++) {
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int[] array = arrayOfArrays[i];
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copied2DArray[i] = Arrays.copyOf(array, array.length);
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}
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return copied2DArray;
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}
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Integer[][] copy2DArray(Integer[][] arrayOfArrays) {
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return Arrays.stream(arrayOfArrays)
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.map(array -> Arrays.copyOf(array, array.length))
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.toArray(Integer[][]::new);
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}
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}
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@@ -1,86 +0,0 @@
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package com.baeldung.array;
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import static org.junit.Assert.assertArrayEquals;
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import static org.junit.Assert.assertEquals;
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import java.io.ByteArrayInputStream;
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import java.io.ByteArrayOutputStream;
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import java.io.InputStream;
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import java.io.PrintStream;
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import org.junit.Test;
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public class MultiDimensionalArrayUnitTest {
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private MultiDimensionalArray obj = new MultiDimensionalArray();
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@Test
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public void whenInitializedUsingShortHandForm_thenCorrect() {
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assertArrayEquals(new int[][] { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } }, obj.shortHandFormInitialization());
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}
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@Test
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public void whenInitializedWithDeclarationAndThenInitalization_thenCorrect() {
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assertArrayEquals(new int[][] { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } }, obj.declarationAndThenInitialization());
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}
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@Test
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public void whenInitializedWithDeclarationAndThenInitalizationUsingUserInputs_thenCorrect() {
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InputStream is = new ByteArrayInputStream("1 2 3 4 5 6 7 8 9".getBytes());
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System.setIn(is);
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assertArrayEquals(new int[][] { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } }, obj.declarationAndThenInitializationUsingUserInputs());
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System.setIn(System.in);
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}
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@Test
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public void givenMultiDimensionalArrayAndAnIndex_thenReturnArrayAtGivenIndex() {
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int[][] multiDimensionalArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
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assertArrayEquals(new int[] { 1, 2 }, obj.getElementAtGivenIndex(multiDimensionalArr, 0));
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assertArrayEquals(new int[] { 3, 4, 5 }, obj.getElementAtGivenIndex(multiDimensionalArr, 1));
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assertArrayEquals(new int[] { 6, 7, 8, 9 }, obj.getElementAtGivenIndex(multiDimensionalArr, 2));
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}
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@Test
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public void givenMultiDimensionalArray_whenUsingArraysAPI_thenVerifyPrintedElements() {
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int[][] multiDimensionalArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
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ByteArrayOutputStream outContent = new ByteArrayOutputStream();
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System.setOut(new PrintStream(outContent));
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obj.printElements(multiDimensionalArr);
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assertEquals("[1, 2][3, 4, 5][6, 7, 8, 9]", outContent.toString().replace("\r", "").replace("\n", ""));
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System.setOut(System.out);
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}
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@Test
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public void givenMultiDimensionalArray_whenUsingArraysFill_thenVerifyInitialize2DArray() {
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int[][] multiDimensionalArr = new int[3][];
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multiDimensionalArr[0] = new int[2];
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multiDimensionalArr[1] = new int[3];
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multiDimensionalArr[2] = new int[4];
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obj.initialize2DArray(multiDimensionalArr);
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assertArrayEquals(new int[][] {{7,7}, {7,7,7}, {7,7,7,7}}, multiDimensionalArr);
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}
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@Test
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public void givenMultiDimensionalArray_whenUsingIteration_thenVerifyFindLengthOfElements() {
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int[][] multiDimensionalArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
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assertArrayEquals(new int[]{2,3,4}, obj.findLengthOfElements(multiDimensionalArr));
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}
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@Test
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public void givenMultiDimensionalArray_whenUsingArraysStream_thenVerifyFindLengthOfElements() {
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Integer[][] multiDimensionalArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
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assertArrayEquals(new Integer[]{2,3,4}, obj.findLengthOfElements(multiDimensionalArr));
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}
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@Test
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public void givenMultiDimensionalArray_whenUsingArraysCopyOf_thenVerifyCopy2DArray() {
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int[][] multiDimensionalArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
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assertArrayEquals(multiDimensionalArr, obj.copy2DArray(multiDimensionalArr));
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}
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@Test
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public void givenMultiDimensionalArray_whenUsingArraysStream_thenVerifyCopy2DArray() {
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Integer[][] multiDimensionalArr = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } };
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assertArrayEquals(multiDimensionalArr, obj.copy2DArray(multiDimensionalArr));
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}
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}
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