１，创建ArrayList的方法

➊食物列表 = 新的数组列表();

２，源代码

一维数组

import java.util.ArrayList;

public class Main {

    public static void main(String[] args) {

        ArrayList<String> food = new ArrayList<String>();

        food.add("pizza");
        food.add("hambueger");
        food.add("hotdog");

        food.set(0, "sushi");
        food.remove(2);
        food.clear();

        for (int i = 0; i < food.size(); i++) {
            System.out.println(food.get(i));
        }
    }

}

二维数组

import java.util.ArrayList;

public class Main {

    public static void main(String[] args) {

        ArrayList<ArrayList<String>> groceryList = new ArrayList<>();

        ArrayList<String> bakeryList = new ArrayList<>();

        bakeryList.add("pasta");
        bakeryList.add("garlic bread");
        bakeryList.add("donuts");

        ArrayList<String> produceList = new ArrayList<>();

        produceList.add("tomatoes");
        produceList.add("zucchini");
        produceList.add("peppers");

        ArrayList<String> drinksList = new ArrayList<>();

        drinksList.add("soda");
        drinksList.add("coffee");

        groceryList.add(bakeryList);
        groceryList.add(produceList);
        groceryList.add(drinksList);

        for (int i = 0; i < groceryList.size(); i++) {
            System.out.println(groceryList.get(i));

        }

    }

}

二维数组和for-each循环。

import java.util.ArrayList;

public class Main {

    public static void main(String[] args) {

        String[] animals = { "cat", "dog", "rat", "bird" };

        for (String animal : animals) {
            System.out.println(animal);
        }

        ArrayList<String> newAnimals = new ArrayList<>();

        newAnimals.add("cat");
        newAnimals.add("dog");
        newAnimals.add("rat");
        newAnimals.add("bird");

        for (String animal : newAnimals) {
            System.out.println(animal);
        }

    }

}

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