如何为多个整数创建1 for循环？

Question

有没有办法只使用一个具有多个整数的 for 循环？目前我只编写了 int num0 的代码。但是有没有办法将 num1，num2，num3 的其余部分放在同一个代码中？我之所以在这里要求这样做，是因为我作为程序员没有经验，我想知道你们是否知道是否有解决方案。（请原谅我的语法不好）

    public void exercise1c() {
      int num0, num1, num2, num3;

      num0 = Integer.parseInt(JOptionPane.showInputDialog("Write a number."));
      num1 = Integer.parseInt(JOptionPane.showInputDialog("Write a number."));
      num2 = Integer.parseInt(JOptionPane.showInputDialog("Write a number."));
      num3 = Integer.parseInt(JOptionPane.showInputDialog("Write a number."));

      for (int i = 0; i <= num0; i++) {
        if (num0 <= 0) {
            System.out.println("Number "+ num0 + " is negative.");
            break;
        }
      }
      if (num0 >= 0) {
        System.out.println(num0 + " is a integer.");
      }
      if (num0 == 0){
        System.out.println(num0 + " is zero.");
      }
    }

Answer 1

首先，这些对象num#不是数组，而是原语，如果它们是整数。如果三个数组的长度相同，答案是肯定的！

for (int i =0; i < numArray.length; i++)

但是如果您正在寻找一种在数组中迭代的快速方法

for (int i : numArray)
     System.out.println("The number is: " + i);

Answer 2

使用数组：

int[] num = new int[4];

num[0] = Integer.parseInt(JOptionPane.showInputDialog("Write a number."));
num[1] = Integer.parseInt(JOptionPane.showInputDialog("Write a number."));
num[2] = Integer.parseInt(JOptionPane.showInputDialog("Write a number."));
num[3] = Integer.parseInt(JOptionPane.showInputDialog("Write a number."));

for(int i = 0; i<num.length; i++) {
    int currentInteger = num[i];

    //other code here...
}

Answer 3

将< code>num0，num1，num2，num3添加到< code >列表或< code >数组中，然后可以使用单个< code>for循环

例如：带 int[]

int[] num = new int[4];
num[0] = Integer.parseInt(JOptionPane.showInputDialog("Write a number."));
num[1] = Integer.parseInt(JOptionPane.showInputDialog("Write a number."));
num[2] = Integer.parseInt(JOptionPane.showInputDialog("Write a number."));
num[3] = Integer.parseInt(JOptionPane.showInputDialog("Write a number."));

for (int i = 0; i < num.length; i++) {
   if (num[i] < 0) {
      System.out.println("Number " + num[i] + " is negative.");
      break;
   }
   if (num[i] > 0) {
      System.out.println(num[i] + " is a integer.");
   }
   if (num[i] == 0) {
      System.out.println(num[i] + " is zero.");
   }
}

如何使用列表执行此操作

例如:

  List<Integer> numList = new ArrayList<>();
  numList.add(Integer.parseInt(JOptionPane.showInputDialog("Write a number.")));
  numList.add(Integer.parseInt(JOptionPane.showInputDialog("Write a number.")));
  numList.add(Integer.parseInt(JOptionPane.showInputDialog("Write a number.")));
  numList.add(Integer.parseInt(JOptionPane.showInputDialog("Write a number.")));

    for (Integer i :numList) {
        if (i < 0) {
            System.out.println("Number " + i + " is negative.");
            break;
        }
        if (i > 0) {
            System.out.println(i + " is a integer.");
        }
        if (i == 0) {
            System.out.println(i + " is zero.");
        }
    }