Introduction

I wanted to deepen my understanding of Java's 2D arrays, so I summarized it.

Sample code

A two-dimensional array is an array that specifies elements with two indexes.

`Main.java`

``````

public class Main {
public static void main(String[] args) throws Exception {

//How to create an array-⑴ * Explanation

//String[][] teams;

//teams = new String[2][3];

//Declaration of array variables
//Specify the number of elements with the new operator and assign it to teams

//How to create an array- ⑵

//String[][] teams = new String[2][3];

//Perform method ⑴ at the same time

//teams[0][0] = "Brave";
//teams[0][1] = "Warrior";
//teams[0][2] = "Wizard";
//teams[1][0] = "Thieves";
//teams[1][1] = "Ninja";
//teams[1][2] = "merchant";

//Store in array

//How to create an array- ⑶
String[][] teams = {{"Brave", "Warrior", "Wizard"},
{"Thieves", "Ninja", "merchant"}};

//Perform from creation to storage at the same time

System.out.println(teams[0][0]);
//Execution result:Brave

teams[0][0] = "Swordsman";
//Hero → Updated to Swordsman

System.out.println(teams[0][0]);
//Execution result:Swordsman

System.out.println(teams.length);
//Execution result:2
//Array length

System.out.println(teams[0].length);
//Execution result:3
//teams[0]Array length of
}
}
``````

Commentary

`Main.java`

``````
teams = new String[n][m];

// n:Number of elements in the array, m:Number of elements in the array stored in the element
``````

In terms of coordinates, the y coordinate is n and the x coordinate is m. For reference, click here!