Question

我正在进行MOOC java课程，而且我仍然坚持练习76.每当我提交答案时，它会告诉我将每餐打印成单独的一行。我该怎么做呢？

主要课程

dispatchTouchEvent

菜单类

ACTION_DOWN

输出

public class Main {
    public static void main(String[] args) {
        Menu exactum = new Menu();


        exactum.addMeal("Fish fingers with sour cream sauce");
        exactum.addMeal("Vegetable casserole with salad cheese");
        exactum.addMeal("Chicken and nacho salad");

        exactum.printMeals();


        exactum.clearMenu();
        exactum.printMeals();
    }
}

Answer 1

只需遍历列表并单独打印每个项目：

  public void printMeals() {
    for(String meal : meals) {
        System.out.println(meal);
    }
  }

Answer 2

在 Java 8

中

public void printMeals() {
    this.meals.stream().forEach(System.out::println);
}

Answer 3

 import java.util.ArrayList;

public class Menu {

   private ArrayList<String> meals;

public Menu() {
    this.meals = new ArrayList<String>();
}

 public void addMeal(String meal) {
     if (!meals.contains(meal)) {
     meals.add(meal);      
 }
}
  public void printMeals() {
   if (meals.isEmpty()){
     System.out.println("No Meal Object Found !");
      return;
    }
for(String meal : meals) {
    System.out.println(meal);
    }
   }
  public void clearMenu(){
      meals.removeAll(meals);
  }
}

如何在多行上打印数组列表？

3 个答案: