A memo of the program that allows you to realize that the probability of dice rolling is about 1/6

About two months have passed since I started studying java anew. I wrote a program that can confirm the convergence of the probability of rolling dice as a summary of the underlying variables, arrays, methods and so on. Execute it on the terminal, enter any number of times, the result will be displayed as a graph, and the probability of each will be calculated. If you shake it about 20,000 times, it will be very close to 1/6.

Dice_Probability.java

import java.util.Scanner;
import java.util.Random;

public class Dice_Probability{
    public static void main(String[] args){
    	Scanner scan = new Scanner(System.in);
        
        System.out.print("Enter the number of times you want to roll the dice> ");
        int times = scan.nextInt();
        
        int[] result = generateDice(times);
        
        System.out.println("Display the result");
        for (int i=0; i<result.length; i++){
        	System.out.printf("%2d", result[i]);
            
            if((i+1) % 10 ==0){
            	System.out.println("");
            }
        }
        
        System.out.println("The graph is as follows.");
        drawGraph(result);
        
        System.out.println("The probability of each eye appearing is");
        double[] percentage = calcProbability(result);
        for (int i=0; i<percentage.length; i++){
        	System.out.println((i+1) + "Eyes: " + percentage[i]);
        }
    }
    
    public static int[] generateDice(int n){
    	Random rand = new Random();
        int[] arr = new int[n];
        
        for (int i=0; i<arr.length; i++){
        	arr[i] = rand.nextInt(6) + 1;
        }
        
        return arr;
    }
    
    public static void drawGraph(int[] arr){//Graph display method
        int[] dottimes = {0,0,0,0,0,0};//Record the number of times the eyes appear
        for (int i=0; i<arr.length; i++){
            switch (arr[i]){
                case 1:
                    dottimes[0]++;
                    break;
                case 2:
                    dottimes[1]++;
                    break;
                case 3:
                    dottimes[2]++;
                    break;
                case 4:
                    dottimes[3]++;
                    break;
                case 5:
                    dottimes[4]++;
                    break;
                case 6:
                    dottimes[5]++;
                    break;
            }
        }
        
        for (int i=0; i<=5; i++){
            System.out.print((i+1) + " : ");//Display of rolls
        	for(int j=0; j<dottimes[i]; j++){//1~dice[i]Times*Show
            	System.out.print("*");
            }
            System.out.println("");//new line
        }
    }
    
    public static double[] calcProbability(int[] arr){//Method for calculating probability. Receives eye data and returns the probability of each eye
        
        int[] dottimes = {0,0,0,0,0,0};
        for (int i=0; i<arr.length; i++){
            switch (arr[i]){
                case 1:
                    dottimes[0]++;
                    break;
                case 2:
                    dottimes[1]++;
                    break;
                case 3:
                    dottimes[2]++;
                    break;
                case 4:
                    dottimes[3]++;
                    break;
                case 5:
                    dottimes[4]++;
                    break;
                case 6:
                    dottimes[5]++;
                    break;
            }
        }
        
        double[] probability = {0,0,0,0,0,0};
        
        for (int i=0; i<dottimes.length; i++){
            probability[i] = (double)dottimes[i]/arr.length;
        }
        
        return probability;
    }
    
    
}