Question

我正在研究一个非常简单的Java问题，我需要在输入某个用户值后停止接收数据。输入值后，用户仍然可以输入数据，但输入值后，输出不应包含该值或该值之后的任何数据。此外，我试图打消负数条目，但无济于事。这是我的代码。任何帮助，将不胜感激！谢谢！

import java.util.Scanner;

public class Sample
{
    public static void main (String[] args) 
    {
        System.out.println("Please input any number, up to 10 entries. "
                + "Enter -1 to exit: ");
        Scanner read = new Scanner(System.in);
        int[] input_array = new int[10];
        int numOfEntries = 0;
        for(int i = 0; i < input_array.length; i++)
        {
            input_array[i] = read.nextInt();
            numOfEntries++;
            //only positive numbers
            if(input_array[i] >= 100 || input_array[i] < 0)
            { 
                if(input_array[i] == 77) //certain value
                { 
                    //entries before 77 is entered become the new array
                    numOfEntries = i;
                    int[] new_array = new int[numOfEntries];
                    for (int j = 0; j < numOfEntries; j++)
                    {
                        new_array[j] = input_array[i];
                    }
                    System.out.print(new_array[numOfEntries] + " ");
                }               
                if(input_array[i] == -1) //exit loop
                {
                    break;
                }
                System.out.println("Please enter a positive 
                number that is less than 100.");
            }
        }   

        //final result
        System.out.println("Your entries are: ");
        for (int i = 0; i < numOfEntries; i++)
        {
            System.out.print(input_array[i] + " ");
        }

Answer 1

您应该像这样检查以确保一切正确通过条件

//all this goes inside the for loop
    String input = read.nextInt();
    if (input == -1)
        break;
    if (input > 0)//is it negative? 
    {
        if (input < 100)//is it greater than 100?
        {
           if (input == 77)//is it 77?
           {
               //your code
           } 
           else//this will run when all conditions are passed
             input_array[i] = input; 
        }
    }

Answer 2

无需创建单独的数组，只有当它是有效值时才添加到初始数组中。检查以下代码，进行了一些修改：

public static void main(String[] args) throws Exception {
        {
            System.out.println("Please input any number, up to 10 entries. " + "Enter -1 to exit: ");
            Scanner read = new Scanner(System.in);
            int[] input_array = new int[10];
            int numOfEntries = 0;
            int entry = 0, status = 0;
            for (int i = 0; i < input_array.length; i++) {
                entry = read.nextInt();
                // only positive numbers
                if (entry < 100 && entry >= 0) {
                    if (entry == 77) // certain value,change the value of 'status' here 
                    {
                        status = 1;
                    }
                    if (status == 0) //if 'status' is not reset,then add the entry to array.
                    {
                        input_array[numOfEntries++] = entry;
                    }

                }  else if (entry == -1) // exit loop
                {
                    break;
                }else {//for negative and values which are greater than 100.
                    System.out.println("Please enter a positive number that is less than 100.");
                }
            }

            // final result
            System.out.println("Your entries are: ");
            for (int i = 0; i < numOfEntries; i++) {
                System.out.print(input_array[i] + " ");
            }
        }
    }

Answer 3

如果你不打算使用它，你不需要添加另一个数组，所以我删除了它并在你的代码中进行了一些修改。请检查以下代码。仔细阅读评论。希望你能理解。

import java.util.Scanner;

public class Sample {
    public static void main(String[] args) {
        System.out.println("Please input any number, up to 10 entries. "
                + "Enter -1 to exit: ");

        int[] input_array = new int[10]; //Input array - size 10
        int input = 0; // input variable
        boolean isInput77 = false; //Check input is 77 (certain value)
        int numOfEntries = 0; // Number of entries that passes your conditions
        Scanner read = new Scanner(System.in);

        for (int i = 0; i < 10; i++) {
            input = read.nextInt(); // input value assign to "input" variables 
            if (input == -1){  // input is -1 break
                break;
            } else if (input == 77){ // input is 77 isInput77 is true
                isInput77 = true;
            } else if (!isInput77 && input < 100 && input >= 0) { // isInput77 is false and input is positive number that is less than 100 add to input_array
                input_array[numOfEntries] = input;
                numOfEntries++;
            } else if(input >= 100 || input < -1){ // input is negative or greater than or equal to 100 
                System.out.println("Please enter a positive number that is less than 100.");
            }
        }

        System.out.println("Your entries are: ");
        for (int i = 0; i < numOfEntries; i++) { // Print only valuable entries
            System.out.print(input_array[i] + " ");
        }
    }
}

某些条目后停止用户输入？

3 个答案: