比较两个String []数组并打印出不同的字符串

我有一个文件夹中的所有文件名以及已由开发人员手动“检查”的文件列表的列表。我将如何去比较这两个数组，以便仅打印那些未包含在主列表中的数组。比较两个String []数组并打印出不同的字符串

public static void main(String[] args) throws java.lang.Exception { 
     String[] list = {"my_purchases", "my_reservation_history", "my_reservations", "my_sales", "my_wallet", "notifications", "order_confirmation", "payment", "payment_methods", "pricing", "privacy", "privacy_policy", "profile_menu", "ratings", "register", "reviews", "search_listings", "search_listings_forms", "submit_listing", "submit_listing_forms", "terms_of_service", "transaction_history", "trust_verification", "unsubscribe", "user", "verify_email", "verify_shipping", "404", "account_menu", "auth", "base", "dashboard_base", "dashboard_menu", "fiveohthree", "footer", "header", "header_menu", "listings_menu", "main_searchbar", "primary_navbar"}; 
     String[] checked = {"404", "account_menu", "auth", "base", "dashboard_base", "dashboard_menu", "fiveohthree", "footer", "header", "header_menu", "listings_menu"}; 

     ArrayList<String> ar = new ArrayList<String>(); 

      for(int i = 0; i < checked.length; i++) 
       { 
        if(!Arrays.asList(list).contains(checked[i])) 
        ar.add(checked[i]); 
       } 
    }

来源

2016-03-21 santafebound

如果我正确理解问题，我会使用嵌套循环并存储未包含在新数组中的名称。 – Logan

更改你的循环到：

ArrayList<String> ar = new ArrayList<String>(); 

for(int i = 0; i < checked.length; i++) 
    { 
     if(!Arrays.asList(list).contains(checked[i])) 
     ar.add(checked[i]); 
    }

ArrayList ar应该是的外面循环。否则ar将在list中每次存在checked数组的元素时创建。

编辑：

if(!Arrays.asList(list).contains(checked))

有了这个说法，你正在检查的checked引用是不是list的元素。应该是checked[i]来检查list中是否存在checked的元素。

如果要打印list中不在checked中的元素。然后使用：

for(int i = 0; i < list.length; i++) 
    { 
     if(!Arrays.asList(checked).contains(list[i])) 
     ar.add(list[i]); 
    } 
System.out.println(ar);

来源

2016-03-21 03:43:37 Satya

谢谢，但打印时出现编译错误。看到我更新的问题。 – santafebound

只需使用'System.out.println（ar）'打印'ar'。内部'toString（）'将在'ar'上被调用。 – Satya

谢谢，你可以在这里看到它：http://ideone.com/AigDCH。似乎没有打印出任何东西。 – santafebound

for (String s: checked) {  // go through all in second list 
    if (! list.contains(s)) { // if string not in master list 
     System.out.println(s); // print that string 
    } 
}

来源

2016-03-21 03:41:50

首先，我觉得你的代码中有一些错误：

S1没有定义
Ar不定义
你的意思是使用Arrays.toString代替Array.toString

因此，我修复了您的代码（使用Java 8），它应该像这样工作：

public static void main(String[] args) throws java.lang.Exception { 
    String[] list = {"my_purchases", "my_reservation_history", "my_reservations", "my_sales", "my_wallet", "notifications", "order_confirmation", "payment", "payment_methods", "pricing", "privacy", "privacy_policy", "profile_menu", "ratings", "register", "reviews", "search_listings", "search_listings_forms", "submit_listing", "submit_listing_forms", "terms_of_service", "transaction_history", "trust_verification", "unsubscribe", "user", "verify_email", "verify_shipping", "404", "account_menu", "auth", "base", "dashboard_base", "dashboard_menu", "fiveohthree", "footer", "header", "header_menu", "listings_menu", "main_searchbar", "primary_navbar"}; 
    String[] checked = {"404", "account_menu", "auth", "base", "dashboard_base", "dashboard_menu", "fiveohthree", "footer", "header", "header_menu", "listings_menu"}; 

    final List<String> result = Stream.of(list) 
      .filter(listEntry -> Stream.of(checked) 
        .filter(checkedEntry -> checkedEntry.equals(listEntry)).findFirst().orElse(null) == null) 
      .collect(Collectors.toList()); 

    System.out.println(result); 
}

如果您不想使用Java 8，则必须替换Streams和过滤器的用法，并使用Java 7中的相应功能（请参阅Satya的文章）进行收集。

不管怎么说，我要指出，有更好的（关于性能）实现，以解决您的问题，例如，

你可以寻找重复之前的列表进行排序，
你可以使用，例如，，基于散列的实现，以提高速度重复搜索时，
你可以移动代码内环以外，
，还有更多

来源

2016-03-21 04:08:36 Philipp

您的更新解决方案对我来说似乎有些奇怪，不知道为什么要将list [i]添加到结果列表中。通常这听起来像一些哈希集是：

String[] list = { "my_purchases", "my_reservation_history","my_reservations","my_sales", "my_wallet", "notifications", "order_confirmation", "payment", "payment_methods", "pricing", "privacy", "privacy_policy", "profile_menu", "ratings", "register", "reviews", "search_listings", "search_listings_forms", "submit_listing", "submit_listing_forms", "terms_of_service", "transaction_history", "trust_verification", "unsubscribe", "user", "verify_email", "verify_shipping", "404", "account_menu", "auth", "base", "dashboard_base", "dashboard_menu", "fiveohthree", "footer", "header", "header_menu", "listings_menu", "main_searchbar", "primary_navbar"}; 
String[] checked = { "404", "account_menu", "auth", "base", "dashboard_base", "dashboard_menu", "fiveohthree", "footer", "header", "header_menu", "listings_menu"}; 

HashSet<String> s1 = new HashSet<String>(Arrays.asList(checked)); 
s1.removeAll(Arrays.asList(list)); 
System.out.println(s1);

来源

2016-03-21 04:45:30

比较两个String []数组并打印出不同的字符串

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