获取整数列表并使用数组反向显示它们

Question

如果我的输入是 1 2 3，输出也是 1 2 3，我如何让这些数字显示 3 2 1？

 public static void main(String[] args) {

    // TODO code application logic here

    Scanner s = new Scanner(System.in);

    String text = s.nextLine();

    String[] entries = text.split(" ");

    int[] nums = new int[entries.length];

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

        nums[i] = Integer.parseInt(entries[i]);

    }

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

        System.out.println(nums[i]);

    }

}

}

Answer 1

如果你想要 Java 8 版本，这里是代码Scanner s = new Scanner(System.in);&nbsp; &nbsp; &nbsp;&nbsp;String text = s.nextLine();&nbsp;String[] entries = text.split("\\s");List<Integer> integers = Arrays.stream(entries)&nbsp; &nbsp; &nbsp; &nbsp; .map(Integer::valueOf)&nbsp; &nbsp; &nbsp; &nbsp; .collect(Collectors.toList());Collections.reverse(integers);integers.forEach(integer -> System.out.print(String.format("%d ", integer)));\\s表示“空白”，我建议你Scanner在最后关闭。

Answer 2

试试下面的代码：public static void main(String[] args)&nbsp;{&nbsp; Scanner s = new Scanner(System.in);&nbsp; String text = s.nextLine();&nbsp; String[] entries = text.split(" ");&nbsp; for(int i = entries.length-1; i >= 0; i--)&nbsp;&nbsp; {&nbsp; &nbsp; &nbsp;System.out.print(Integer.parseInt(entries[i])+ " ");&nbsp; }}

Answer 3

如果要以相反的顺序存储数字：for(int i = 0; i < entries.length; i++){&nbsp; &nbsp; &nbsp;nums[i] = Integer.parseInt(entries[entries.length-i-1]);&nbsp;}&nbsp;如果您只想以相反的顺序显示数字（它们在列表中将保持相同的顺序：for(int i = entries.length-1; i >= 0; i--){&nbsp; &nbsp; System.out.println(nums[i]);&nbsp;}

Answer 4

您可以entries向后循环遍历数组。这将涉及从负 1int i的长度开始entries（因为这是您数组中的最后一个索引 - 即您的最后一个数字）。它还需要您继续循环 while i >= 0。i最后，您需要减少变量，而不是增加变量。这样，您的计数器i将从循环结束到数组的开始（例如：如果输入“1 2 3”，i将从索引开始：2、1、0）请参见下面的示例：public static void main(String[] args) {&nbsp; &nbsp;// TODO code application logic here&nbsp; &nbsp;Scanner s = new Scanner(System.in);&nbsp; &nbsp;String text = s.nextLine();&nbsp; &nbsp;String[] entries = text.split(" ");&nbsp; &nbsp;int[] nums = new int[entries.length];&nbsp; &nbsp;for(int i = 0; i < entries.length; i++) {&nbsp; &nbsp; &nbsp;nums[i] = Integer.parseInt(entries[i]);&nbsp; &nbsp;}&nbsp; &nbsp;for(int i = entries.length-1; i >= 0; i--) {&nbsp; &nbsp; &nbsp;System.out.println(nums[i]);&nbsp; &nbsp;}}