数组值输出多个答案

【问题标题】：Array Value Output more than one数组值输出多个
【发布时间】：2017-11-12 05:00:10
【问题描述】：

这是我想出的代码。但是，我希望能够输出：

（值）在插槽 x 中。
（值）在插槽 x 中。

如果 (value) 在两个插槽中可用，则输出两个 - 如 7。

或

(num) 不在数组中。

但不是两者兼而有之。 有人可以帮忙吗？

    public static void main(String[] args) {
    int search, counter;
    int num[]={3, 4, 5, 6, 7, 8, 10, 7,  9, 13};

    System.out.print("Array: ");
    for (int count=0; count<num.length; count++)
        System.out.print(+num[count] + " ");

    Scanner in = new Scanner (System.in);
    System.out.print("\nValue to find: ");
    search = in.nextInt();

    for (counter = 0; counter < num.length; counter++ ){
        if (num[counter] == search)
        {
            System.out.println(search + " is in slot " + (counter + 1) + ".");
        }           
    }
    if (counter == num.length)
        {
            System.out.println(search + " is not in the array.");
        }
}
}

【问题讨论】：

标签： java arrays loops conditional-statements linear-search

【解决方案1】：

虽然我觉得您可能应该在另一个社区（例如 https://codereview.stackexchange.com/）上提出这样的问题，但我可以提供一个建议：

使用布尔标志来检查您之前是否找到过它。像这样的：

public static void main(String[] args) {
  int search;
  boolean found = false;
  int num[]={3, 4, 5, 6, 7, 8, 10, 7,  9, 13};

  System.out.print("Array: ");
  for (int count=0; count<num.length; count++)
      System.out.print(+num[count] + " ");

  Scanner in = new Scanner (System.in);
  System.out.print("\nValue to find: ");
  search = in.nextInt();

  for (int counter = 0; counter < num.length; counter++ ) {
      if (num[counter] == search)
      {
        System.out.println(search + " is in slot " + (counter + 1) + ".");
        found = true;
      }           
  }

  if (!found) {
        System.out.println(search + " is not in the array.");
  }

  in.close();

}

因此，只有在线性遍历数组后找不到元素时才会打印“未找到”消息...

【讨论】：

假设使用布尔标志是最合适的解决方法。

【解决方案2】：

您的代码的问题是您检查计数器是否已达到数组长度。总会发生的事情。您应该检查是否找到了值。

这应该可以解决问题：

public static void main(String[] args) {
    int search, counter;
    int num[]={3, 4, 5, 6, 7, 8, 10, 7,  9, 13};
    boolean wasFound = false;

    System.out.print("Array: ");
    for (int count=0; count<num.length; count++)
        System.out.print(+num[count] + " ");

    Scanner in = new Scanner (System.in);
    System.out.print("\nValue to find: ");
    search = in.nextInt();

    for (counter = 0; counter < num.length; counter++ ){
        if (num[counter] == search)
        {
            System.out.println(search + " is in slot " + (counter + 1) + ".");
            wasFound = true;
        }
    }
    if (!wasFound)
    {
        System.out.println(search + " is not in the array.");
    }
}

【讨论】：