How to return a 2d array in java?

  1. //Length.
  2. int[][]arr= new int [filas][columnas];
  3. arr. length=filas;
  4. int[][] a = {
  5. {1, 2, 3},
  6. {4, 5, 6, 9},
  7. {7},

How do I return a 2D array?

Use Pointer to Pointer Notation to Return 2D Array From Function in C++ As an alternative, we can use a pointer to pointer notation to return the array from the function. This method has an advantage over others if the objects to be returned are allocated dynamically.

How do you initialize a 2D array in Java?

  1. int[][] multiples = new int[4][2]; // 2D integer array with 4 rows and 2 columns String[][] cities = new String[3][3]; // 2D String array with 3 rows and 3 columns.
  2. int[][] wrong = new int[][]; // not OK, you must specify 1st dimension int[][] right = new int[2][]; // OK.

How do you return a matrix in Java?

  1. import java.util.Arrays;
  2. public class ReturnArrayExample1.
  3. {
  4. public static void main(String args[])
  5. {
  6. int[] a=numbers(); //obtain the array.
  7. for (int i = 0; i < a.length; i++) //for loop to print the array.
  8. System.out.print( a[i]+ ” “);

What is a 2D array in Java?

Similar to a 1-D array, a 2-D array is a collection of data cells. 2-D arrays work in the same way as 1-D arrays in most ways; however, unlike 1-D arrays, they allow you to specify both a column index and a row index. All the data in a 2D array is of the same type.

Can you have a 2D ArrayList?

Creating a multidimensional ArrayList often comes up during programming. In many cases, there is a need to create a two-dimensional ArrayList or a three-dimensional ArrayList.

How do you pass a 2D array to a function pointer?

  1. #include
  2. // Here, the parameter is a pointer to a pointer. void assign(int **arr, int m, int n)
  3. { // assign values to the allocated memory.
  4. for (int i = 0; i < m; i++) {
  5. for (int j = 0; j < n; j++) { *(*(arr + i) + j) = i + j;
  6. } }
  7. }
  8. // Program to pass the 2D array to a function in C. int main(void)

How do I return a local array in C++?

A local array cannot be directly returned from a C++ function as it may not exist in memory after the function call. A way to resolve this is to use a static array in the function. As the lifetime of the static array is the whole program, it can easily be returned from a C++ function without the above problem.

How do you pass a 2D array by reference?

  1. Specify the size of columns of 2D array void processArr(int a[][10]) { // Do something }
  2. Pass array containing pointers void processArr(int *a[10]) { // Do Something } // When callingint *array[10]; for(int i = 0; i < 10; i++) array[i] = new int[10]; processArr(array);

How do you initialize a 2D array to 0?

In C++ you can initialize a one dimensional array with 0 with a code like this: int myarray[100] = {0};

How do you initialize a 2D array to 0 in Java?

  1. int rows = 5, column = 7; int[][] arr = new int[rows][column];
  2. for (int row = 0; row < arr. length; row++)
  3. { for (int col = 0; col < arr[row]. length; col++)
  4. { arr[row][col] = 5; //Whatever value you want to set them to.

How do 2D arrays work in Java?

In Java, a table may be implemented as a 2D array. Each cell of the array is a variable that can hold a value and works like any variable. As with one dimensional arrays, every cell in a 2D array is of the same type. The type can be a primitive type or an object reference type.

Can you return an ArrayList in Java?

Returning an ArrayList is quite convenient. All you need to do is use the ‘return’ keyword. The method that returns nothing uses the keyword ‘void’ in the method declaration else it needs a return type for this purpose. For instance, a method that returns integer values uses ‘int’ as a return type.

How do you return in Java?

return is a reserved keyword in Java i.e, we can’t use it as an identifier. It is used to exit from a method, with or without a value. return can be used with methods in two ways: Methods returning a value : For methods that define a return type, return statement must be immediately followed by return value.

How do you return an empty array in Java?

Return an Empty Array Using new int[0] in Java If the array has a length of zero, then it does not contain any element. To return an empty array from a function, we can create a new array with a zero size. In the example below, we create a function returnEmptyArray() that returns an array of int .