java - 如何从用户交互中生成新变量？

Question

我正在使用 Eclipse，并且有一个一般性编程问题。我想在每次用户执行诸如按下按钮之类的操作时创建一个新变量。如果要创建一个变量一次那就很简单了；在按下按钮的代码中我会声明 -

字符串标题1 =“标题1”;

但是，我希望每次用户单击按钮时都会创建一个新的不同变量。我尝试了不同的方法，例如使用 for 循环来修改下一个变量的名称，但几乎没有想法，所以来这里问我的第一个问题。

谢谢大家，如果这是一个愚蠢的问题，我深表歉意。

Answer 1

你说的这些是做不到的。您可以做的是使用 ArrayList<String>您可以添加 String在用户点击时。

SSCCE:

import java.util.*;

public class ArrayListExamples {

    public static void main(String args[]) {
        // Creating an empty array list
        ArrayList<String> list = new ArrayList<String>();

        // Adding items to arrayList
        list.add("Item1");
        list.add("Item2");
        list.add(2, "Item3"); // it will add Item3 to the third position of
                                // array list
        list.add("Item4");

        // Display the contents of the array list
        System.out.println("The arraylist contains the following elements: "
                + list);

        // Checking index of an item
        int pos = list.indexOf("Item2");
        System.out.println("The index of Item2 is: " + pos);

        // Checking if array list is empty
        boolean check = list.isEmpty();
        System.out.println("Checking if the arraylist is empty: " + check);

        // Getting the size of the list
        int size = list.size();
        System.out.println("The size of the list is: " + size);

        // Checking if an element is included to the list
        boolean element = list.contains("Item5");
        System.out
                .println("Checking if the arraylist contains the object Item5: "
                        + element);

        // Getting the element in a specific position
        String item = list.get(0);
        System.out.println("The item is the index 0 is: " + item);

        // Retrieve elements from the arraylist

        // 1st way: loop using index and size list
        System.out
                .println("Retrieving items with loop using index and size list");
        for (int i = 0; i < list.size(); i++) {
            System.out.println("Index: " + i + " - Item: " + list.get(i));
        }

        // 2nd way:using foreach loop
        System.out.println("Retrieving items using foreach loop");
        for (String str : list) {
            System.out.println("Item is: " + str);
        }

        // 3rd way:using iterator
        // hasNext(): returns true if there are more elements
        // next(): returns the next element
        System.out.println("Retrieving items using iterator");
        for (Iterator<String> it = list.iterator(); it.hasNext();) {
            System.out.println("Item is: " + it.next());
        }

        // Replacing an element
        list.set(1, "NewItem");
        System.out.println("The arraylist after the replacement is: " + list);

        // Removing items
        // removing the item in index 0
        list.remove(0);

        // removing the first occurrence of item "Item3"
        list.remove("Item3");

        System.out.println("The final contents of the arraylist are: " + list);

        // Converting ArrayList to Array
        String[] simpleArray = list.toArray(new String[list.size()]);
        System.out.println("The array created after the conversion of our arraylist is: "
                        + Arrays.toString(simpleArray));
    }
}  

来源:http://examples.javacodegeeks.com/core-java/util/arraylist/arraylist-in-java-example-how-to-use-arraylist/