feat(docs): add multidimensional arrays docs

uiuxarghya · uiuxarghya · commit 77c06273baec · 2024-10-25T10:47:38.000Z
diff --git a/src/pages/docs/multidimensional-arrays.mdx b/src/pages/docs/multidimensional-arrays.mdx
@@ -0,0 +1,208 @@
+---
+title: Java Multidimensional Arrays
+description: In this tutorial, we will learn how to use the Java continue statement to skip the current iteration of a loop.
+---
+
+## Java Multidimensional Arrays
+Before we learn about the multidimensional array, make sure you know about Java array.
+
+A multidimensional array is an array of arrays. Each element of a multidimensional array is an array itself. For example,
+
+```java
+int[][] a = new int[3][4];
+```
+Here, we have created a multidimensional array named a. It is a 2-dimensional array, that can hold a maximum of 12 elements,
+
+![2-dimensional array in Java](https://via.placeholder.com/600x400?text=2-dimensional+array+in+Java)
+2-dimensional Array
+
+Remember, Java uses zero-based indexing, that is, indexing of arrays in Java starts with 0 and not 1.
+
+Let's take another example of the multidimensional array. This time we will be creating a 3-dimensional array. For example,
+
+```java
+String[][][] data = new String[3][4][2];
+```
+Here, data is a 3d array that can hold a maximum of 24 (3*4*2) elements of type [String](/docs/string).
+
+### How to initialize a 2d array in Java?
+Here is how we can initialize a 2-dimensional array in Java.
+
+```java
+int[][] a = {
+    {1, 2, 3}, 
+    {4, 5, 6, 9}, 
+    {7}, 
+};
+```
+As we can see, each element of the multidimensional array is an array itself. And also, unlike C/C++, each row of the multidimensional array in Java can be of different lengths.
+
+
+![2d array example in Java with variable length](https://via.placeholder.com/600x400?text=2d+array+example+in+Java+with+variable+length)
+Initialization of 2-dimensional Array
+
+### Example: 2-dimensional Array
+```java
+class MultidimensionalArray {
+    public static void main(String[] args) {
+
+        // create a 2d array
+        int[][] a = {
+            {1, 2, 3}, 
+            {4, 5, 6, 9}, 
+            {7}, 
+        };
+      
+        // calculate the length of each row
+        System.out.println("Length of row 1: " + a[0].length);
+        System.out.println("Length of row 2: " + a[1].length);
+        System.out.println("Length of row 3: " + a[2].length);
+    }
+}
+```
+#### Output:
+
+```plaintext
+Length of row 1: 3
+Length of row 2: 4
+Length of row 3: 1
+```
+In the above example, we are creating a multidimensional array named a. Since each component of a multidimensional array is also an array (`a[0]`,`a[1]` and `a[2]` are also arrays).
+
+Here, we are using the `length` attribute to calculate the length of each row.
+
+### Example: Print all elements of 2d array Using Loop
+
+```java
+class MultidimensionalArray {
+    public static void main(String[] args) {
+
+        int[][] a = {
+            {1, -2, 3}, 
+            {-4, -5, 6, 9}, 
+            {7}, 
+        };
+      
+        for (int i = 0; i < a.length; ++i) {
+            for(int j = 0; j < a[i].length; ++j) {
+                System.out.println(a[i][j]);
+            }
+        }
+    }
+}
+```
+#### Output:
+
+```plaintext
+1
+-2
+3
+-4
+-5
+6
+9
+7
+```
+We can also use the [for...each loop](/docs/enhanced-for-loop) to access elements of the multidimensional array. For example,
+
+```java
+class MultidimensionalArray {
+    public static void main(String[] args) {
+
+        // create a 2d array
+        int[][] a = {
+            {1, -2, 3}, 
+            {-4, -5, 6, 9}, 
+            {7}, 
+        };
+      
+        // first for...each loop access the individual array
+        // inside the 2d array
+        for (int[] innerArray: a) {
+            // second for...each loop access each element inside the row
+            for(int data: innerArray) {
+                System.out.println(data);
+            }
+        }
+    }
+}
+```
+Output:
+
+```plaintext
+1
+-2
+3
+-4
+-5
+6
+9
+7
+```
+In the above example, we are have created a 2d array named `a`. We then used `for` loop and `for...each` loop to access each element of the array.
+
+### How to initialize a 3d array in Java?
+Let's see how we can use a 3d array in Java. We can initialize a 3d array similar to the 2d array. For example,
+
+```java
+// test is a 3d array
+int[][][] test = {
+        {
+          {1, -2, 3}, 
+          {2, 3, 4}
+        }, 
+        { 
+          {-4, -5, 6, 9}, 
+          {1}, 
+          {2, 3}
+        } 
+};
+```
+Basically, a 3d array is an array of 2d arrays. The rows of a 3d array can also vary in length just like in a 2d array.
+
+### Example: 3-dimensional Array
+```java
+class ThreeArray {
+    public static void main(String[] args) {
+
+        // create a 3d array
+        int[][][] test = {
+            {
+              {1, -2, 3}, 
+              {2, 3, 4}
+            }, 
+            { 
+              {-4, -5, 6, 9}, 
+              {1}, 
+              {2, 3}
+            } 
+        };
+
+        // for..each loop to iterate through elements of 3d array
+        for (int[][] array2D: test) {
+            for (int[] array1D: array2D) {
+                for(int item: array1D) {
+                    System.out.println(item);
+                }
+            }
+        }
+    }
+}
+```
+#### Output:
+
+```plaintext
+1
+-2
+3
+2
+3
+4
+-4
+-5
+6
+9
+1
+2
+3
+```
