Tag: arraylist

java – Create ArrayList from array

The Question : 3685 people think this question is useful I have an array that is initialized like: I would like to convert this array into an object of the ArrayList class. The Question Comments : In Java9 –> List<String> list = List.of(“Hello”, “World”, “from”, “Java”); @MarekM This answer is wrong, as this doesn’t return

java – Create ArrayList from array

The Question : 3685 people think this question is useful I have an array that is initialized like: I would like to convert this array into an object of the ArrayList class. The Question Comments : In Java9 –> List<String> list = List.of(“Hello”, “World”, “from”, “Java”); @MarekM This answer is wrong, as this doesn’t return

java – Initialization of an ArrayList in one line

The Question : 2853 people think this question is useful I wanted to create a list of options for testing purposes. At first, I did this: ArrayList<String> places = new ArrayList<String>(); places.add("Buenos Aires"); places.add("Córdoba"); places.add("La Plata"); Then, I refactored the code as follows: ArrayList<String> places = new ArrayList<String>( Arrays.asList("Buenos Aires", "Córdoba", "La Plata")); Is there

java – Create ArrayList from array

The Question : 3685 people think this question is useful I have an array that is initialized like: Element array = {new Element(1), new Element(2), new Element(3)}; I would like to convert this array into an object of the ArrayList class. ArrayList<Element> arraylist = ???; The Question Comments : In Java9 –> List<String> list =

java – Remove object from object ArrayList

The Question : 0 people think this question is useful I have created an object ArrayList, private ArrayList<Object> objects; and I am initializing it in a constructor. public ObjectManager(Handler handler) { this.handler = handler; objects = new ArrayList<>(); } This ArrayList is then painted/added it to a canvas. public void renderObjects(Graphics g) { handler.getObjectManager().addObject(new InstanceOfObject(handler,

何时通过ArrayList使用LinkedList?

我一直只使用一个: List<String> names = new ArrayList<>(); 我使用接口作为可移植性的类型名称,以便当我提出这些问题时,我可以重写我的代码。 什么时候应该LinkedList用完,ArrayList反之亦然? TL; DR ArrayList与ArrayDeque在优选的多更多的用例比LinkedList。不知道 – 刚开始ArrayList。 LinkedList并且ArrayList是List接口的两个不同的实现。LinkedList用双链表实现它。ArrayList用动态调整大小的数组来实现它。 与标准链表和数组操作一样,各种方法将具有不同的算法运行时。 对于 LinkedList<E> get(int index)是O(n / 4)平均值 add(E element)是O(1) add(int index, E element)是O(n / 4)的平均值, 但O(1)时index = 0 <—主要受益LinkedList<E> remove(int index)是O(n / 4)平均值 Iterator.remove()是O(1) <—的主要好处之一LinkedList<E> ListIterator.add(E element)是O(1) <—的主要好处之一LinkedList<E> 注:O(n / 4)是平均值,O(1)最好情况(例如索引= 0),O(n / 2)最差情况(列表中) 对于 ArrayList<E> get(int index)是O(1) <—的主要好处之一ArrayList<E> add(E element)是O(1)分期付款,但O(n)最坏的情况,因为数组必须调整大小并复制 add(int index, E element)是O(n / 2)平均值 remove(int

PHP result from two arrays pairing dates where key is “Y”

问题内容: I have two array $array1 = array("2017-12-08","2017-12-09","2017-12-10","2017-12-11","2017-12-12","2017-12-13","2017-12-14","2017-12-15","2017-12-16","2017-12-17","2017-12-18","2017-12-19","2017-12-20","2017-12-21","2017-12-22"); $array2 = array("Y","Y","Y","Y","Y","N","N","N","Y","Y","Y","N","N","Y","Y"); I need the first and last date where the key=”Y”. Like this: $result = array("2017-12-08 - 2017-12-12", "2017-12-16 - 2017-12-18", "2017-12-21 - 2017-12-22"); How i can make this? I have tried with array_combine but after that I do not know how to list the