I know a map is a data structure that maps keys to values. Isn’t a dictionary the same? What is the difference between a map and a dictionary1? 1. I am not asking for how they are defined in language X or Y (which seems to be what generally people are asking here on SO), … Read more
This question already has answers here: A Java collection of value pairs? (tuples?) (21 answers) Closed 2 years ago. I’m looking for a KeyValuePair class in Java. Since java.util heavily uses interfaces there is no concrete implementation provided, only the Map.Entry interface. Is there some canonical implementation I can import? It is one of those … Read more
It’s difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 9 years ago. The community reviewed whether to reopen this question … Read more
I am finding some difficulty in accessing mutable dictionary keys and values in Objective-C. Suppose I have this: NSMutableDictionary *xyz=[[NSMutableDictionary alloc] init]; I can set keys and values. Now, I just want to access each key and value, but I don’t know the number of keys set. In PHP it is very easy, something as … Read more
I’d like to create new item that similarly to Util.Map.Entry that will contain the structure key, value. The problem is that I can’t instantiate a Map.Entry because it’s an interface. Does anyone know how to create a new generic key/value object for Map.Entry? 11 Answers 11
Based on an associative array in a Bash script, I need to iterate over it to get the key and value. #!/bin/bash declare -A array array[foo]=bar array[bar]=foo I actually don’t understand how to get the key while using a for-in loop. 5 Answers 5
From post: Sending a JSON array to be received as a Dictionary<string,string> I’m trying to do this same thing as that post. The only issue is that I don’t know what the keys and the values are upfront. So I need to be able to dynamically add the key and value pairs and I don’t … Read more
I have an object of the type IEnumerable<KeyValuePair<T,U>> keyValueList, I am using var getResult= keyValueList.SingleOrDefault(); if(getResult==/*default */) { } else { } How can I check whether getResult is the default, in case I can’t find the correct element? I can’t check whether it is null or not, because KeyValuePair is a struct. 8 Answers … Read more
I am looking for a better pattern for working with a list of elements which each need processed and then depending on the outcome are removed from the list. You can’t use .Remove(element) inside a foreach (var element in X) (because it results in Collection was modified; enumeration operation may not execute. exception)… you also … Read more
I’m looking for a class in java that has key-value association, but without using hashes. Here is what I’m currently doing: Add values to a Hashtable. Get an iterator for the Hashtable.entrySet(). Iterate through all values and: Get a Map.Entry for the iterator. Create an object of type Module (a custom class) based on the … Read more