Can I have an hashMap with say ID as my key and info, name, quantity as my values? ok, say I have a class (Products) already that sets my variables, getters and setters. In my Invoice class, which is where the hashMap would be. Would I put like: private HashMap<String, Products> keys = new HashMap<String, Products> I'm not quite sur...
I'm using a 'Properties' class in Java which inherits from HashMap. I'm building a basic compiler in hashmap. I know it can be simplified using something besides a hashmap. Here is the my code... Properties inputSource = new Properties(); inputSource.put("ERROR", "ERROR"); inputSource.put("GET", "GET"); inputSource.put("PRINT", "PRINT"...
Possible Duplicate: how to sort hash map How do I sort a HashMap? ...
how datas arranged in Hashmap? ...
Hi all, I am having a little dilemma with a C++ code. Its actually a performance issue. I am trying to traverse through two hash_maps which is causing a lot of slowness. Heres the hash map class code. Let me know if I am missing something from this. template<class Handle, class Object, class HashFunc, vector<Object *> (*initFunc)()> ...
How do I convert LinkedHashMap to java.util.HashMap in groovy? When I create something like this in groovy, it automatically creates a LinkedHashMap even when I declare it like HashMap h = .... or def HashMap h = ... I tried doing: HashMap h = ["key1":["val1", "val2"], "key2":["val3"]] and def HashMap h = ["key1":["val1", "val2"],...
from p.46 "Effective Java" Joshua Bloch. Item 9: ALways override hashCode when you override equals Some class PhoneNumber overrides equals() and doesn't override hashCode() "two instances are involved: one is used for insertion into the HashMap, and a second, equal, instance is used for (attempted) retrieval." ... "... Even if the two ...
Hi all, This is a trivial programming question. I am not an expert in Java. Say I use objects of custom classes Company and Employee, in a manner similar to what many RDBMS examples do: class Employee { Company company; } class Company { String name; } I need to guarantee that different Company objects have unique names - i....
Hi there I have page gets given an ArrayList<Document> where each document has a property called type. I don't know the number of unique types or documents. I want to sort this ArrayList into a HashMap<type, document[]> but am having some trouble getting my head around it. Some pseudo-code would like like for (int i = 0; i < documen...
I've been looking around for encryption and I've seen several implementations of Rainbow Tables work like charm on passwords (say windows). I'm yet to see an implementation of a Rainbow attack on a RAR file. Why is it so. What makes RAR encryption more secure and immune to these sorts of attacks? ...
How can I use eval in groovy to evaluate the following String: {key1=keyval, key2=[listitem1, listitem2], key3=keyval2} All the list items and keyval is a String. doing Eval.me("{key1=keyval, key2=[listitem1, listitem2], key3=keyval2}") is giving me the following error: Ambiguous expression could be either a parameterless closure exp...
Hi! It has been reported that from Java JDK 1.3.1 to JDK 1.4.0 HashMap is 5 times slower (see here). What is the state of the art of HashMap at java 6? Is recommendable to be used? Thanks, Luis ...
I am unit testing java code from ScalaTest and would like to populate a java.util.HashMap within the same statement it gets declared. Is it possible to do this in Scala? ...
I have a HashMap and now i need to find all the keys inside the HashMap which has a particular letter inside it and replace it with another letter ...
In the below code, hash_map is automatically sorting or maybe inserting elements in a sorted order. Any ideas why it does this?? Suggestions Please?? This is NOT a homework problem, trying to solve an interview question posted on glassdoor dot com. #include <iostream> #include <vector> #include <ext/hash_map> #include <map> #include <st...
I was asked this in an interview: "Tell me everything you know about hashmaps." I proceeded to do just that: it's a data structure with key-value pairs; a hash function is used to locate the element; how hash collisions can be resolved, etc. After I was done, they asked: "OK, now explain everything you just said to a 5-year-old. You c...
Hi guys, I want to merge Two HashMaps. I could use map1.putAll(map2); but I don't want to overwrite the key's as yes they will have conflicting keys. So the keys in each map will be like this word1 word1 word2 word2 word3 word3 and when I merge them I would like: word1 word2 word3 word4 word5 word6 It c...
What's the syntax to set immutable hashmap contents on initialization? For example, if I was willing to hardcode an array, I'd write: val a = Array (0, 1, 2, 3) What's the analogue for immutable hashmaps (say I want it to contain 0->1 and 2->3 pairs) (in Scala 2.8)? ...
I just want to know how to, if a Hashmap is already on the list add 1 to quantity, if it is not then add it to list. This is what I've done that just add eventhough the item is already on list. list = new ArrayList<HashMap<String, String>>(); Cursor c = db.rawQuery("SELECT code,desc,price FROM TbLPrice WHERE code =" + txtCode.getText()....
Hi, I have a ListView showing names of Countries. I have stored the names in strings.xml as a string-array called country_names. In populating the ListView, I use an ArrayAdapter which reads from strings.xml String[] countryNames = getResources().getStringArray(R.array.country_names); ArrayAdapter<String> countryAdapter = new ArrayAd...