小编Pra*_*ran的帖子

我在Windows 7(64位)计算机上的DOS控制台中运行以下命令.

npm install -g yarn
yarn add global react-native
yarn add global react-native-cli

react-native init sample

运行后react-native init sample,控制台已关闭.

错误日志显示:

D:\Mobile>"$basedir/../../Users/pramaswamy/AppData/Local/Yarn/.global/node_modules/.bin/react-native.cmd"   "$@" 

D:\Mobile>exit $? 

好吧,我有一个非常烦人的错误.它来自我的retainAll方法.问题是我最后输出了1,3,5的整数,但我需要1,3,5,7,9.以下是MySet和驱动程序类的代码

public class MySetTester {

    public static void main(String[]args) {
        MySet<String> strings = new MySet<String>();
        strings.add("Hey!");
        strings.add("Hey!");
        strings.add("Hey!");
        strings.add("Hey!");
        strings.add("Hey!");
        strings.add("Listen!");
        strings.add("Listen!");
        strings.add("Sorry, I couldn't resist.");
        strings.add("Sorry, I couldn't resist.");
        strings.add("(you know you would if you could)");
        System.out.println("Testing add:\n");
        System.out.println("Your size: " + strings.size()
                        + ", contains(Sorry): " + strings.contains("Sorry, I couldn't resist."));
        System.out.println("Exp. size: 4, contains(Sorry): true\n");
        MySet<String> moreStrings = new MySet<String>();
        moreStrings.add("Sorry, I couldn't resist.");
        moreStrings.add("(you know you would if you could)");
        strings.removeAll(moreStrings);
        System.out.println("Testing remove and removeAll:\n");
        System.out.println("Your …

这是我的代码

boolean isWithinRange(String d)
{
    boolean withinDate = false;   
    try
    {
        DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
        Date date = dateFormat.parse(d);
        withinDate = !(date.before(startDate) || date.after(endDate));
    }
    catch (ParseException parseException)
    {
     }
    return withinDate;
}

输入

2015-11-26
2015-11-26 - 复制

两者都返回 true，但我需要的是“2015-11-26”应该为 true，“2015-11-26 - Copy”应该为 false。

为什么我在执行以下代码时遇到异常.

  String[] array1 = {"A","B","C","D","E"};
  String[] array2 = {"F","G","H","I"}; 
  List<String> list = Arrays.asList(array1);
  list.addAll(Arrays.asList(array2)); //here getting exception

例外

 Exception in thread "main" java.lang.UnsupportedOperationException
at java.util.AbstractList.add(Unknown Source)
at java.util.AbstractList.add(Unknown Source)
at java.util.AbstractCollection.addAll(Unknown Source)
at Sample6.main(Sample6.java:19)

但是这段代码运作良好.

List<String> list = new ArrayList<String>(Arrays.as.asList(array1));        
list.addAll(Arrays.asList(array2));

谢谢

代码的正则表达式

    String inputOne = "cat cat cat cattie cat";
    String findStr = "cat";
    Pattern p = Pattern.compile("cat");
    Matcher m = p.matcher(inputOne);
    int countOne = 0;
    while (m.find()) {
        countOne++;
    }
    System.out.println("Match number " + countOne);

代码的字符串比较

   String inpuTwo = "cat cat cat cattie cat";
   int lastIndex = 0;
   int count = 0;
   while (lastIndex != -1) {
       lastIndex = inpuTwo.indexOf("cat", lastIndex);
       if (lastIndex != -1) {
            count++;
            lastIndex += findStr.length();
       }
   }
   System.out.println("Match number " + count);

在两者中都会在输入字符串"cat cat cat …