Intellij IDEA：Java 找不到 getRandomElement

Question

I want to make a simple number guessing game, but I cannot print a random number, because java will not let me use getRandomElement.

Compiler error:

 The method getRandomElement() is undefined for the type Main

Code:

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

public class Main {

    // Drive Function 
    public static void main(String[] args) {

        // create a list of Integer type 
        List<Integer> list = new ArrayList<>();
        // add 5 element in ArrayList 
        list.add(10);
        list.add(20);
        list.add(30);
        list.add(40);
        list.add(50);

        Main obj = new Main();

        // take a random element from list and print them 
        System.out.println(obj.getRandomElement(list));
    }
}

Answer 1

You are missing getRandomElement method in your class, you forgot to create/copy as method in example

public int getRandomElement(List<Integer> list) { Random rand = new Random(); return list.get(rand.nextInt(list.size())); }