arraylist

Counting duplicate values in Hashmap

由 浪子不回头ぞ 提交于 2020-01-02 10:07:43
问题 I have a hash map that looks like this: HashMap<String, ArrayList<String>> varX = new HashMap<String, ArrayList<String>>(); And I can't for the life of me work out how to count the number of duplicate values. For example, If put("001", "DM"); into the hash map and put("010", "DM"); as well, how can count if there are two values int the ArrayList section of the Hashmap. For example, the output would look something like this: DM:2 as I 'put' two DM values into the Hashmap. 回答1: You have a

Create jTable with ArrayList

由 那年仲夏 提交于 2020-01-02 09:57:28
问题 I searched for a while but I cant find a solution for my problem. I want to display the Values of an ArrayList in a JTable, i'm pretty new to this and cant fix the error. package Statistik; import java.util.ArrayList; import javax.swing.JFrame; import javax.swing.JScrollPane; import javax.swing.JTable; public class Statistic { private static ArrayList<String> rowA = new ArrayList(); private static ArrayList<String> rowB = new ArrayList(); private static ArrayList<String> rowC = new ArrayList(

Iterating ArrayList inside a method

由 社会主义新天地 提交于 2020-01-02 09:43:10
问题 I have a Candidades class that holds Candidate objects, as follow: import java.util.*; public class Candidates<Candidate> extends ArrayList<Candidate> { public int getTotalVotesCount() { Iterator it = this.iterator(); int i, total = 0; while(it.hasNext()) { Candidate c = (Candidate)it.next(); total += c.getVoteCount(); } return total; } } Class Candidate is as follows: public class Candidate { private int votes; private String name; public String getName() { return this.name; } public int

Using Binary Search to add to an ArrayList in order

由 天大地大妈咪最大 提交于 2020-01-02 08:56:59
问题 Hello everyone hoping you can help me here, My problem is that I need to be able to search through an ArrayList using binary search and find where the correct place to add an object so that the list stays in order. I cannot use the collections sort as this is a homework. I have correctly implemented a boolean method that tells if the list contains an item you want to search for. That code is here: public static boolean search(ArrayList a, int start, int end, int val){ int middle = (start +

Java集合框架（一）

由 久未见 提交于 2020-01-02 08:30:21
原文 http://www.jianshu.com/p/e31fb2600e4f 集合类存放于java.util包中，集合类存放的都是对象的引用，而非对象本身，出于表达上的便利，我们称集合中的对象就是指集合中对象的引用（reference) 集合类型主要有3种：set(集）、list(列表）和map(映射) 通俗的说，集合就是一个放数据的容器，准确的说是放数据对象引用的容器 Collection接口 Collection 是最基本的集合接口，一个 Collection 代表一组 Object，即 Collection 的元素，Java不提供直接继承自Collection的类，只提供继承于的子接口(如List和set) Collecton接口常用的子接口有：List接口、Set接口 List接口常用的子类有：ArrayList类、LinkedList类 Set接口常用的子类有：HashSet类、LinkedHashSet类如 接口多态的调用 Collection<String> collection = new ArrayList<String>(); 741560-20170330144456389-1484217347.png 注意 学习Java中三种长度表现形式 数组 .length 属性，返回值 int 字符串 .length() 方法，返回值 int 集合 .size()

how to sort particular strings from an array of values in php?

由 一个人想着一个人 提交于 2020-01-02 07:47:06
问题 $array = array("2011-September_38","2011-June_4","2010-November_9","2011-November_29","2010-December_19"); i want to sort this array strings as following, it should sort the year first, then it should sort the month, DESIRED OUTPUT Array ( [0] => 2010-Marh_19 [1] => 2010-November_9 [2] => 2011-June_4 [3] => 2011-September_38 [4] => 2011-November_29 ) I've tried something, could anyone bind my function to sort year then month http://codepad.org/skEiUkTC 回答1: Try this code: <?php $array = array

Converting nested ArrayList into List Java

由 妖精的绣舞 提交于 2020-01-02 07:15:38
问题 I have this method public List<List<Stat>> ConvertReportCases (ArrayList<ArrayList<Stat>> stats) It is an interface implementation where the return type is a List<List<Stat>> . In general how do I convert from a nested ArrayList to List in Java? Thanks Edit Thanks for the suggestions I could make my parameter passed as List but then it would be wrong since the caller will have to pass it as List, whereas in my particular case I could have different versions (polymorphism) to check this issue.

save the data using shared preference in android

由 自闭症网瘾萝莉.ら 提交于 2020-01-02 06:55:29
问题 i am new developer in android applications.i would like to save the data using shared preference concept.i am saving the data in one activity and get the same data in another activity.here i would like to send the String a[]={"one","two","three"} one activity to another activity.i have written code as follows Main1.java public class Main1 extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main);

java multi mapping arraylist

由 我只是一个虾纸丫 提交于 2020-01-02 04:47:05
问题 Is it possible to map key to Multi Dimensional Array List. Some thing like following example.. Map<K,V> Where K is key for list of alphabet and V is a multi dimensional array list or normal array list that stores list of word. Some thing like a application that reads a dictionary file. I want to see an example. Example can be anything related to Map and Multi Dimensional Array-list. Or is there any other efficient way to implement collection? I have never used such implementations so if there

Move specific items to the end of a list

由 对着背影说爱祢 提交于 2020-01-02 03:51:32
问题 I have an ArrayList in Java : {"deleteItem", "createitem", "exportitem", "deleteItems", "createItems"} I want to move all string which contains delete to the end of the list, so I would get the next: {"createitem", "exportitem", "createItems", "deleteItem", "deleteItems"}` I can create two sublists - one for the words which contain the 'delete' word, and one for the others, and then merge them, but I search for a more efficient way. 回答1: Use custom Comparator: List<String> strings = Arrays
订阅 arraylist