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!

Java, about 2D arrays

Introduction

Sample code

Main.java

Commentary

Main.java

`Main.java`

`Main.java`