Course Content
Java Basics
Java Basics
Iteration In Two-Dimensional Array
How to Iterate Inside Two-Dimensional Array Using a for-loop?
Iterating through a two-dimensional array can be a bit challenging to grasp initially, so don't worry if it doesn't click right away. In this chapter, I'll demonstrate how to do it and explain how it functions.
We use a nested loop to iterate through a two-dimensional array, meaning one loop inside another. The outer loop iterates over the rows, while the inner loop iterates over the columns. Let's examine the syntax for iterating through a two-dimensional array using the example array we created in the previous chapter:
Main
package com.example; public class Main { public static void main(String[] args) { int[][] twoDimensionalArray = { {1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}, {13, 14, 15, 16} }; for (int i = 0; i < twoDimensionalArray.length; i++) { for (int j = 0; j < twoDimensionalArray[0].length; j++) { System.out.print(twoDimensionalArray[i][j] + " "); } System.out.println(); } } }
Let's delve into the meaning of each element in the code snippet provided above:
int[][] twoDimensionalArray =
- This line initializes a two-dimensional array;for (int i = 0; i < twoDimensionalArray.length; i++)
- The first for-loop iterates over the rows of our matrix. While we're on the first row, our program enters the nested loop, which doesn't impact the outer loop. The variablei
represents the current row number;for (int j = 0; j < twoDimensionalArray[0].length; j++)
- The second for-loop iterates over the columns of the matrix. While we're on the 0th row, we iterate through the columns of that row. The variablej
represents the current column number;System.out.print(twoDimensionalArray[i][j] + " ");
- In this line, we useSystem.out.print
to display our values in a single line. Let's see how it operates: while we're on the 0th row, we iterate through the columns on that row. For example,array[0][1]
, followed byarray[0][2]
, and so on. We continue through the columns as long asj
is less thanarray[0].length
. Once we reacharray[0].length
, we return to the outer array and move to the first row. For example,array[0][3] -> array[1][0]
. We've reached our boundaries and then transitioned to row 1.
Swipe to show code editor
Your task is to locate and display the diagonal (from the top-left corner to the bottom-right corner) of the provided matrix on the screen:
Note
The diagonal represents a line in the matrix where the row and column numbers are identical.
Thanks for your feedback!
Iteration In Two-Dimensional Array
How to Iterate Inside Two-Dimensional Array Using a for-loop?
Iterating through a two-dimensional array can be a bit challenging to grasp initially, so don't worry if it doesn't click right away. In this chapter, I'll demonstrate how to do it and explain how it functions.
We use a nested loop to iterate through a two-dimensional array, meaning one loop inside another. The outer loop iterates over the rows, while the inner loop iterates over the columns. Let's examine the syntax for iterating through a two-dimensional array using the example array we created in the previous chapter:
Main
package com.example; public class Main { public static void main(String[] args) { int[][] twoDimensionalArray = { {1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}, {13, 14, 15, 16} }; for (int i = 0; i < twoDimensionalArray.length; i++) { for (int j = 0; j < twoDimensionalArray[0].length; j++) { System.out.print(twoDimensionalArray[i][j] + " "); } System.out.println(); } } }
Let's delve into the meaning of each element in the code snippet provided above:
int[][] twoDimensionalArray =
- This line initializes a two-dimensional array;for (int i = 0; i < twoDimensionalArray.length; i++)
- The first for-loop iterates over the rows of our matrix. While we're on the first row, our program enters the nested loop, which doesn't impact the outer loop. The variablei
represents the current row number;for (int j = 0; j < twoDimensionalArray[0].length; j++)
- The second for-loop iterates over the columns of the matrix. While we're on the 0th row, we iterate through the columns of that row. The variablej
represents the current column number;System.out.print(twoDimensionalArray[i][j] + " ");
- In this line, we useSystem.out.print
to display our values in a single line. Let's see how it operates: while we're on the 0th row, we iterate through the columns on that row. For example,array[0][1]
, followed byarray[0][2]
, and so on. We continue through the columns as long asj
is less thanarray[0].length
. Once we reacharray[0].length
, we return to the outer array and move to the first row. For example,array[0][3] -> array[1][0]
. We've reached our boundaries and then transitioned to row 1.
Swipe to show code editor
Your task is to locate and display the diagonal (from the top-left corner to the bottom-right corner) of the provided matrix on the screen:
Note
The diagonal represents a line in the matrix where the row and column numbers are identical.
Thanks for your feedback!