hashmap

问题 I have a HashMap defined as such: public Map<Integer, String> staticBlockPositions = new HashMap<Integer, String>(); I am iterating over the map by getting each key, like this: for (Integer key : blockPositions.keySet()) { System.out.println(key); } My question is, can I rely on the value of key to always be in ascending order. So if my HashMap looks something like this: { 4: "abc123", 1: "def456", 11: "qwe789", 10: "iop019" } (I know this is JSON format, this is just so you get an idea of

问题 How would you initialise a static Map in Java? Method one: Create a Class extend from Hashmap as below Here is an example illustrating the way i did using a CustomMap: 回答1: public class CustomMap < K, V > extends java.util.HashMap < K, V > { public CustomMap(Object[]...objs) { super(); this.of(objs); } public java.util.Map < K, V > of(Object[]...objs) { for (Object[] o: objs) { this.of((K) o[0], (V) o[1]); } return this; } public java.util.Map < K, V > of(K k, V v) { this.put(k, v); return

问题 I have received some C++ code that I am trying to compile under Linux 64 bits using the provided makefiles. In that code there is a string_hash.h file containing the code: #ifndef STRING_HASH #define STRING_HASH #include <string> #include "universal_hash_map.h" #ifdef WINDOWS typedef stdext::hash_compare<std::string> String_Hasher; typedef stdext::hash_map< std::string, std::string, stdext::hash_compare<std::string> > String_Hash; #else #ifdef LINUX class String_Hasher: public stdext::hash<

问题 I´m trying to write the code for the problem described in my previous topic. The suggested solution was to use hashmaps to find similar entries in multiple arrays (arrays have the same number of columns, but they might have different number of rows). Below is my sample code based on a code snippet of the user John B provided here. For simplicity and for debugging purpose, I created just 3 different one-dimensional rows instead of two-dimensional arrays. Also, for simplicity, the function

问题 This question already has answers here : Understanding strange Java hash function (6 answers) Closed 4 years ago . I see that the implementation of the hashmap applies some kind of transformation to the hashCode to get the actual hash. Could some one please help me understand how this transformation works and additionally if it would make any difference if the object to store is just an integer? 回答1: As taken from the Javadoc of the method hash(Object) in the OpenJDK Java 8 HashMap

问题 I have one model called Person with properties name image age amount and I have a singleton hashmap Hashmap<String,Person> globalPersonList which contains list of person objects. I am trying to retrieve one single object from my hashmap like Person existingPerson = globalPersonList.get("key"); I want to create a new Person instance and initiallize with existingPerson properties like Person person = new Person(); person = globalPersonList.get("key"); Now I want to set amount field to this

问题 Im new to Android. What i need is?.. Can i get two string values in a single hashmap, its possible. I have two hashmaps,these two hashmap values should i get in another hashmap. How to implement this? Any help.. Thanks in advance.. String question = c.getString(TAG_QUES); System.out.println("Checking ::"+question); HashMap<String, String> map = new HashMap<String, String>(); map.put(TAG_QUES,question); System.out.println("questionMap:"+map); ques1.add(question); String answer = c.getString

问题 Hi in my project i have to fetch a contacts phone number and the name from the phone.I can get call the phone number and name but when i add it to the ArrayList<HashMap<String, String>> i'm getting the only the last value i don't know why. but when i log it i'm getting all the value can u guys help me where did i go wrong public class Contacts extends Activity { Button btnGetContacts; int z = 1; String namereview = null; public String phoneNumber1 = "", phoneNumber, name1, url,urljoingroup;

问题 This question already has answers here : How to declare global variables in Android? (17 answers) Closed 4 months ago . I have one problem is i am parsing data from google api which returns me JSON data. I stored that data in HashMap<string,String>. which is dynamic. Now i want to make it accessible in my another classes of application. so i am confuse how to make it accessible in other classes without making static. is there any solution? if u have any sample code please send. i tried using

问题 I want to implement the averaged perceptron algorithm, in accordance with this description (page 48, complete with psuedocode). I think I'm pretty close, but I'm having trouble trying to figure out the last step wherein I need to compute the average of the weights calculated during every iteration for each particular index, and then assign that value to a final array of weights. How would I implement that? The structure of the hashmap is int which is the number of iterations, and then an