How To Loop Over 2 Dimensional Array Inwards Java?

You tin flame loop over a two-dimensional array inward Java past times using two for loops, too known as nested loop. Similarly to loop an n-dimensional array y'all ask n loops nested into each other. Though it's non mutual to run across an array of to a greater extent than than three dimension too 2D arrays is what y'all volition run across most of the places. It's i of the most useful information construction inward the programming world. You tin flame operate a two-dimensional array to brand finite solid soil machine (FSM) solve solid soil based problems, y'all tin flame operate a 2D array to create board games similar Chess, Sudoku too Tic-Tac-To too y'all tin flame fifty-fifty operate a two-dimensional array to create 2D arcade games e.g. Tetris, Super Mario Bros too thence on. Whatever y'all run across on your covert is zero but a 2D array which is populated using tiles.

In lodge to brand operate of the 2D array, y'all must know how to populate too iterate over it too that's what y'all volition larn inward this article. You tin flame yell back virtually 2 dimensional array as a matrix which has rows too columns, this aid to visualize contents of an array. In lodge to loop over a 2D array, nosotros kickoff acquire through each row too and thence over again nosotros acquire through each column inward every row. That's why nosotros ask 2 loops, nested inward each other.

Anytime, if y'all desire to come upwardly out of nested loop, y'all tin flame operate the interruption statement. If y'all are an absolute beginner too only started alongside programming, I recommend reading Head First Programming first. Once y'all went through the book, most of the programming concept e.g. array, string, vector volition brand feel to you.

Java Program to Loop over 2D Array inward Java

Here is a Java plan to iterate over a 2 dimensional array inward Java using traditional for loop. Though it's non necessary to operate for loop, y'all tin flame fifty-fifty operate piece loop or advanced for loop inward Java, it makes feel to start alongside this simplest of programming construct.

In this example, nosotros accept kickoff created a 2 dimensional array of size 4x4, which way four rows too four columns. Then nosotros accept looped over it 2 times, kickoff fourth dimension to populate the array alongside integer values too the minute fourth dimension to acquire through each index too impress their values.

It's non necessary to start looping from kickoff chemical cistron e.g. [0, 0] which is kickoff row too kickoff column but if y'all desire to impact every chemical cistron this is the correct house to start.

Here is the code to loop over 2D array inward Java :

 for (int row = 0; row < board.length; row++) {     for (int col = 0; col < board[row].length; col++) {        board[row][col] = row * col;     }  }

You tin flame run across that outer loop is going through each row too the inner loop is going through each column, this way nosotros acquire over all elements. In the kickoff iteration, all elements of the kickoff row are processed, only similar iterating over i dimensional array.

Here is the consummate plan :

Looping over 2D array inward Java

/**  * Java Program to demonstrate how to loop over two-dimensional array.  * We kickoff loop to populate the array too subsequently to impress values.   *   * @author WINDOWS 8  */ public class TwoDimensionalArrayDemo{      public static void main(String args[]) {          // let's create board of 4x4         int[][] board = new int[4][4];          // let's loop through array to populate board         for (int row = 0; row < board.length; row++) {             for (int col = 0; col < board[row].length; col++) {                 board[row][col] = row * col;             }         }          // let's loop through array to impress each row too column         for (int row = 0; row < board.length; row++) {             for (int col = 0; col < board[row].length; col++) {                 board[row][col] = row * col;                 System.out.print(board[row][col] + "\t");             }             System.out.println();         }     }  }

Output :

0   0   0   0    0   1   2   3    0   2   4   6    0   3   6   9    

BTW, Java doesn't actually accept multi-dimensional arrays, instead, y'all accept arrays of arrays (of arrays ...). So, if y'all desire to loop through the kickoff array, y'all inquire for "board[0].length", if y'all desire to loop through the minute array, y'all inquire for "board[1].length".

As I told you, a multi-dimensional array is i of the pop information construction too tin flame endure used to stand upwardly for board games e.g. Chess, Ludo, Sudoku, Tetris too too every bit useful to describe terrains inward tile based games. In fact, it is i of the most useful information construction inward game programming. Another natural operate of a multi-dimensional array is inward matrix maths e.g. matrix multiplication, adding 2 matrices, transposing matrices etc.

You tin flame extend this technique to loop through the multi-dimensional array inward Java. You volition only ask as many loops as many dimension your array has. Remember, y'all tin flame declare a two-dimensional array inward Java without specifying the length of the minute dimension.

Further Learning
Data Structures too Algorithms: Deep Dive Using Java
here)

22 Array concept Interview Questions inward Java (see here)

How to impress array values inward Java? (example)

How to compare 2 arrays inward Java? (example)

Data Structures too Algorithm Analysis inward Java (see here)

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