Question

我的意思是，如果我有一个由空格分隔的数组，我如何区分两个连续的字符是否是两个或更多个数字？跟我一起，我对编程一般都很陌生。

这是我到目前为止所做的：

import java.util.*;
    public class calc 
    {
        public static String itemList;
        public static String str;
        public static void main(String[] args) 
        {
            Scanner sc = new Scanner(System.in);
            str = sc.nextLine();
            delimitThis();
            sc.close();
        }
        public static void delimitThis()// Delimiter to treat variable and                 numbers as seperate
        {
            List<String> items = Arrays.asList(str.split("\\s+"));
            System.out.println(items);

            for (int i = 0; i < str.length(); i++) 
             {
                    itemList = items.get(i);
                    category();

             }  
        }
        public static void category()////For Filtering between vars and constants and functions
        {
            for (int x = 0; x < itemList.length(); x++)
            {
               char ite = itemList.charAt(x);
        if(Character.isDigit(ite))
        {
            System.out.println(ite + "is numeric"); //Will be replaced by setting of value in a 2 dimensional list
            }
        }
    }

Answer 1

首先，我想解决你的错误：

错误1：

// bad
for (int i = 0; i < str.length(); i++) 
{
    itemList = items.get(i);
    category();
}

您正在浏览List<String> items，但正在使用str.length。这是错误的。要为category()中的每个项目 {打印项然后items}，代码应为：

// fixed
for (int i = 0; i < items.size(); i++)
{
    itemList = items.get(i);
    category();
}

错误2：

for (int x = 0; x < itemList.length(); x++)
{
   System.out.println(itemList);
}

我不确定你在这里想做什么。只是你的代码对我没有意义。我假设你想从itemList打印每个字符行，代码应如下所示：

for (int x = 0; x < itemList.length(); x++)
{
   System.out.println(itemList.charAt(x));
}

完成错误。现在检查字符串是否包含2位数字或更多，我们可以String.matches()使用regular expression：

if(itemList.matches("\\d\\d+")){
    System.out.println(itemList + " is a two or more digit number");
}else{
    System.out.println(itemList + " is NOT a two or more digit number");
}

代码最终看起来像这样：

import java.util.*;
public class Calc
{
    public static String itemList;
    public static String str;
    public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
        str = sc.nextLine();
        delimitThis();
        sc.close();
    }
    public static void delimitThis()// Delimiter to treat variable and numbers as seperate
    {
        List<String> items = Arrays.asList(str.split("\\s+"));
        System.out.println(items);

        for (int i = 0; i < items.size(); i++)
        {
            itemList = items.get(i);
            category();
        }
    }
    public static void category()////For Filtering between vars and constants and functions
    {
        for (int x = 0; x < itemList.length(); x++)
        {
            System.out.println(itemList.charAt(x));
        }

        // is 2 digit number or not?
        if(itemList.matches("\\d\\d+")){
            System.out.println(itemList + " is a two or more digit number");
        }else{
            System.out.println(itemList + " is NOT a two or more digit number");
        }
    }
}

Answer 2

要检查字符串是否至少为2位数字，请使用此正则表达式：Set<CompletableFuture<String>> futures = service.getSomething(); for (CompletableFuture<String> future : futures) { System.out.println(future.get()); }。

Set<CompletableFuture<String>> futures = service.getSomething();
Set<CompletableFuture<String>> donefutures = new HashSet<>();

while (true) {
    if (futures.equals(donefutures)) {
        break;
    }

    futures
            .stream()
            .filter(f -> !donefutures.contains(f))
            .filter(CompletableFuture::isDone)
            .peek(donefutures::add)
            .map(f -> {
                try {
                    return f.get();
                } catch (InterruptedException | ExecutionException e) {
                    return null;
                }
            })
            .forEach(System.out::println);

    Thread.sleep(100);
}

如何确定char条目是两位数还是多位数？

2 个答案: