When would you use a java.util.LinkedList

Possible Duplicate: When to use LinkedList<> over ArrayList<>? This is a genuine attempt to know when would one use a LinkedList; From what i understand since the java.util.LinkedList doesn't support random access, the only way to get the nth element is to skip from 1 to (n-1) or use get(n) which itself is very inefficient. So why would one use a LinkedList? An ArrayList w

你什么时候会使用java.util.LinkedList

可能重复: 何时通过ArrayList <>使用LinkedList <>? 这是一个真正的尝试,知道什么时候会使用LinkedList; 据我所知,因为java.util.LinkedList不支持随机访问,所以获得第n个元素的唯一方法是从1跳到(n-1)或使用get(n),这本身效率非常低。 那么为什么会使用LinkedList呢? 除非你想用ListIterator从两边迭代集合,否则一个ArrayList可以用于大多数情况? 想想这个方法: List list = // choose you

Difference in LinkedList and ArrayList implementation?

Possible Duplicate: When to use LinkedList<> over ArrayList<>? I saw the API for the ArrayList and LinkedList and it seems to be same. Apart from their performance difference is there any difference in terms of adding, deleting and iterating the List. List arrList = new ArrayList(); List linList = new LinkedList(); The List arrList or linList reference is actually implementing

LinkedList和ArrayList实现的区别?

可能重复: 何时通过ArrayList <>使用LinkedList <>? 我看到了ArrayList和LinkedList的API,它看起来是一样的。 除了它们的性能差异之外,在添加,删除和迭代列表方面还有什么不同。 List arrList = new ArrayList(); List linList = new LinkedList(); List arrList or linList引用实际上正在实现相应的类。 这实际上意味着什么? 当你问到“这究竟是什么意思?”时,我不是100%确定你的意思,但这是一

Insertion in the middle of ArrayList vs LinkedList

This question already has an answer here: When to use LinkedList over ArrayList? 28 answers The reason here is that there's no actual shifting of elements in the linked list. A linked list is built up from nodes, each of which holds an element and a pointer to the next node. To insert an element into a list requires only a few things: create a new node to hold the element; set the

插入ArrayList vs LinkedList中间

这个问题在这里已经有了答案: 何时通过ArrayList使用LinkedList? 28个答案 这里的原因是链接列表中元素没有实际移动。 链表由节点构成,每个节点都包含一个元素和一个指向下一个节点的指针。 要将元素插入列表只需要几件事情: 创建一个新节点来保存元素; 将前一个节点的下一个指针设置为新节点; 将新节点的下一个指针设置为列表中的下一个元素。 如果您制作了一系列回形针,您可以将每个回形针视为其链条的开

Difference between arraylist and linkedList

Possible Duplicate: When to use LinkedList<> over ArrayList<>? When to use a linked list over an array/array list? When should I use arrayList and when should I go for LinkedList? When should I use TreeSet , LinkedHashSet and HashSet ? When should i use arrayList and when should I go for LinkedList? Arraylist maintain indices like arrays. So if want more frequent get operat

arraylist和linkedList之间的区别

可能重复: 何时通过ArrayList <>使用LinkedList <>? 何时通过数组/列表使用链表? 什么时候应该使用arrayList,什么时候应该使用LinkedList? 什么时候应该使用TreeSet , LinkedHashSet和HashSet ? When should i use arrayList and when should I go for LinkedList? Arraylist维护像数组一样的索引。 所以如果想要比操作更频繁的操作,那么ArrayList是最好的选择。 LinkedList维护指向元素的指针

Which one runs faster, ArrayList or LinkedList?

This question already has an answer here: When to use LinkedList over ArrayList? 28 answers Performance differences between ArrayList and LinkedList 9 answers If you have to perform lots of inserts and not-so-frequent lookup, use a LinkedList . Use ArrayList if you perform more lookup than inserts. The reason is as follows - ArrayList is backed by an array which has an initial capacity.

哪一个运行速度更快,ArrayList或LinkedList?

这个问题在这里已经有了答案: 何时通过ArrayList使用LinkedList? 28个答案 ArrayList和LinkedList之间的性能差异9个答案 如果你必须执行大量的插入和不太频繁的查找,请使用LinkedList 。 如果执行比插入更多的查找,请使用ArrayList 。 原因如下 - ArrayList由具有初始容量的数组支持。 因此,如果不断插入项目到列表中,有一次它将不得不重新调整它的数组容量以适应新插入的项目,并且如果执行索引 - 特定插入,

Why is "final" not allowed in Java 8 interface methods?

One of the most useful features of Java 8 are the new default methods on interfaces. There are essentially two reasons (there may be others) why they have been introduced: Providing actual default implementations. Example: Iterator.remove() Allowing for JDK API evolution. Example: Iterable.forEach() From an API designer's perspective, I would have liked to be able to use other modifi

为什么在Java 8接口方法中不允许“final”?

Java 8最有用的功能之一是接口上的新default方法。 基本上有两个原因(可能还有其他原因)为什么被引入: 提供实际的默认实现。 示例: Iterator.remove() 允许JDK API进化。 例如: Iterable.forEach() 从API设计者的角度来看,我希望能够在接口方法上使用其他修饰符,例如final 。 这在添加便利方法时很有用,可以防止实现类中的“意外”覆盖: interface Sender { // Convenience method to send an empty messa

How to make a new List in Java

We create a Set as: Set myset = new HashSet() How do we create a List in Java? List myList = new ArrayList(); or with generics (Java 8 or later) List<MyType> myList = new ArrayList<>(); or with generics (Old java versions) List<MyType> myList = new ArrayList<MyType>(); 另外,如果你想创建一个包含事物的列表(虽然它将是固定的大小): List<String> messages = Array

如何在Java中创建一个新的List

我们创建一个Set为: Set myset = new HashSet() 我们如何在Java中创建一个List ? List myList = new ArrayList(); 或泛型(Java 8或更高版本) List<MyType> myList = new ArrayList<>(); 或与泛型(旧的Java版本) List<MyType> myList = new ArrayList<MyType>(); 另外,如果你想创建一个包含事物的列表(虽然它将是固定的大小): List<String> messages = Arrays.asList("Hello", "Wo

Merge two lists in constant time in Java

Does anyone know if it's possible to merge two lists (or any collection) in constant time in Java ? http://www.cppreference.com/wiki/stl/list/splice It's so easy to do that using linked lists in C... Thanks, The classes in the JDK library don't support this, as far as I know. It's possible if you build your own implementation of List - which you're free to do, it'

用Java在常量时间内合并两个列表

有谁知道是否可以在Java中定时合并两个列表(或任何集合)? http://www.cppreference.com/wiki/stl/list/splice 在C中使用链接列表很容易 谢谢, 就我所知,JDK库中的类不支持这一点。 如果您构建自己的List实现(您可以自由执行),那么这是完全合法的。 您可以使用LinkedList并识别要添加的集合也是LinkedList的特例。 在记录你的课程时,你需要指出添加的对象成为新对象的一部分,换句话说,失去了很多普遍性。

Override back button to act like home button

On pressing the back button, I'd like my application to go into the stopped state, rather than the destroyed state. In the Android docs it states: ...not all activities have the behavior that they are destroyed when BACK is pressed. When the user starts playing music in the Music application and then presses BACK, the application overrides the normal back behavior, preventing the player

重写后退按钮以充当主页按钮

在按下后退按钮时,我希望我的应用程序进入停止状态,而不是被破坏的状态。 在Android文档中,它指出: ......并非所有活动都具有在按下BACK时被销毁的行为。 当用户在音乐应用程序中开始播放音乐,然后按下BACK时,应用程序将覆盖正常的后退行为,防止播放器活动被破坏,并继续播放音乐,即使其活动不再可见 如何在我自己的应用程序中复制此功能? 我认为必须有三种可能性...... 捕获后退按钮(如下所示),然后调用

How do I cleanup an opened Process in Java?

I'm starting a Process from a Java program. I hold onto it and at later points in the program I may send it some signals (not as in UNIX signals -- a different mechanism) to tell it to clean itself up and shut down, which is the proper way of terminating this process. I may later restart and hold onto the process and stop it again an arbitrary number of times. I'd like my program, whe

如何清理Java中打开的Process?

我从一个Java程序开始一个过程。 我坚持下去,在程序的后面,我可能会发送一些信号(不像UNIX信号 - 一种不同的机制),告诉它清理和关闭,这是终止这个过程的正确方法。 我稍后可能会重新启动并保持该进程并再次停止任意次数。 当我的程序存在时,我想让程序指示终止并确保它存在。 否则,由于Java以异步方式启动进程,因此它会在程序终止后继续运行并继续运行。 我以为我会在析构函数中为包含Process变量的对象执行此操