Assertion 用法

import java.util.Scanner;

public class Demo {
    public static void main(String[] args){
    
        Scanner scanner = new Scanner(System.in);
        System.out.print("Please input positive number:");
        int input = scanner.nextInt();
        if (input > 0){
            System.out.println("Number: " + input);
        } else {
            assert (input > 0): "執行有誤....";
            System.out.println("Error : " + input);
        }
    }
}