map

问题 This question already has answers here : Closed 9 years ago . Possible Duplicate: What are the reasons why Map.get(Object key) is not (fully) generic This method and a number of other methods in the Map interface are not generic. Almost anywhere a key value is expected as a parameter, it accepts Object instead, namely remove, get and containsKey. Any idea as to why they made this decision. My assumption is that it was done to support legacy code, but to me, I think that is a weak position.

问题 I am using MapBox example and I have imported my own mbtiles file. I am getting this error: "MB Example[8517:c07] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '* -[NSURL initFileURLWithPath:]: nil string parameter'. The default mbtiles file is working fine. What am I doing wrong here? 回答1: You are likely not properly bundling the MBTiles file with your app. Be sure that it is added to your app target and is part of the Copy Bundle Resources build phase so

问题 I have an array of strings: ["username", "String", "password", "String"] And I want to convert this array to a list of Field objects: class Field attr_reader :name, :type def initialize(name, type) @name = name @type = type end end So I need to map "username", "String" => Field.new("username", "String") and so on. The length of the array will always be a multiple of two. Does anyone know if this is possible using a map style method call? 回答1: 1.8.6: require 'enumerator' result = [] arr = [

问题 I have a key type: struct KeyT { uint32_t timestamp; // example! uint32_t a; uint32_t b; uint32_t c; uint32_t d; uint32_t e; // ... bool operator== (const KeyT& key) const { if(timestamp == key.timestamp && a == key.a && b == key.b && d == key.d && c == key.c && e == key.e) return true; return false; } bool operator< (const KeyT& key) const { if(timestamp < key.timestamp) return true; else if(timestamp == key.timestamp && a < key.a && b < key.b && c < key.c && d < key.d && e < key.e) return

问题 When I am searching "Rudy barber Shop, New York" string in http://maps.google.com, google map showing 10 results... But When I am using google map api in my App, It only returning two results http://maps.googleapis.com/maps/api/geocode/xml?address=Rudy%20barber%20Shop,%20New%20York&sensor=false Now my question is that how can get the same result. Thanks Mandeepd 回答1: I don't think you can get exactly the same results as in Google Maps. Google Maps is a whole application . It uses multiple

问题 I'm looking into an associative array library in C (which I didn't write). Similar to a map in C++ or Python's dict's. There are some non-standard hashing functions which I'm not certain if they are even very good. (maybe the original developer just threw some magic-numbers, xor-operators and hoped for the best) . I wrote a test which measures how well the hashing function performs given some sample input, to measure how evenly it distributes items into a fixed number of buckets (modulo array

问题 I am using UISearchDisplaycontroller .. In my viewcontroller user can search place aftert i have update mapview and setting searchtableview hidden propety is YES. In iOS 7 I am not able to scroll and get touch event on mapview. But in iOS 6 it will work.. After pressing cancel button i am able to scroll and touch event on map view. You can see below screenshot. Thanks in advance 回答1: I could solve my problem with help of another question Here by setting self.searchDisplayController

问题 How do I get a subset of a map? Assume we have val m: Map[Int, String] = ... val k: List[Int] Where all keys in k exist in m . Now I would like to get a subsect of the Map m with only the pairs which key is in the list k . Something like m.intersect(k) , but intersect is not defined on a map. One way is to use filterKeys : m.filterKeys(k.contains) . But this might be a bit slow, because for each key in the original map a search in the list has to be done. Another way I could think of is k.map

问题 How do I get a subset of a map? Assume we have val m: Map[Int, String] = ... val k: List[Int] Where all keys in k exist in m . Now I would like to get a subsect of the Map m with only the pairs which key is in the list k . Something like m.intersect(k) , but intersect is not defined on a map. One way is to use filterKeys : m.filterKeys(k.contains) . But this might be a bit slow, because for each key in the original map a search in the list has to be done. Another way I could think of is k.map

问题 I have a List of HashMap 's which has key of type Integer and value of type Long . List<HashMap<Integer, Long>> ListofHash = new ArrayList<HashMap<Integer, Long>>(); for (int i = 0; i < 10; i++) { HashMap<Integer, Long> mMap = new HashMap<Integer, Long>(); mMap.put(Integer.valueOf(i), Long.valueOf(100000000000L+i)); ListofHash.add(mMap); } Now, how do I retrieve the key and value from the list of HashMap ? If using Collection class is the solution, please enlight me. Update 1: Actually i am