key-value

In .NET can I use any string as a dictionary key? This is part of a templating engine and I'm planning allow users to add their custom headers and values. Headers will be something like "Value of X" or "Summary of Analyse & XYZ Reports", I'm worried if they would get an exception in a rare character or something like that. I assume there size limit but expecting it to be larger than 256 characters. MSDN hasn't got any details on the subject. Mehrdad Afshari Yes, it can use any valid string (which is limited to a couple billion bytes). BTW, you might pass a custom IEqualityComparer<T> that you

原题链接在这里： https://leetcode.com/problems/time-based-key-value-store/ 题目： Create a timebased key-value store class TimeMap , that supports two operations. 1. set(string key, string value, int timestamp) Stores the key and value , along with the given timestamp . 2. get(string key, int timestamp) Returns a value such that set(key, value, timestamp_prev) was called previously, with timestamp_prev <= timestamp . If there are multiple such values, it returns the one with the largest timestamp_prev . If there are no values, it returns the empty string ( "" ). Example 1: Input: inputs = ["TimeMap","set

Can somebody tell me please if is possible to use field value as key in mongodb result. If I have documentes like {'code': 'xxx', 'item': 'yyy'} {'code': 'ooo', 'item': 'eee'} I would like to get result where code value will be the key like {'xxx': 'yyy'}, {'ooo': 'eee'} You have to use $arrayToObject if you want to build your keys dynamically. It takes an array of k and v fields as a parameter. To make it root you can use $replaceRoot stage, try: db.col.aggregate([ { $replaceRoot: { newRoot: { $arrayToObject: [ [ { k: "$code", v: "$item" } ] ]} } } ]) I don't think thats possible. Mongo

I have a dictionary < string,object > which has a mapping of a string and a dictionary < string,int >. How do I add a key value pair in the inside dictionary < string ,int > ? Dictionary <string,object> dict = new Dictionary <string,object>(); Dictionary <string,int> insideDict = new Dictionary <string,int>(); // ad some values in insideDict dict.Add("blah",insideDict); So now the dict has a dictionary mapped with a string.Now I want to separately add values to the insideDict. I tried dict["blah"].Add(); Where am I going wrong? Something like below Dictionary<string, object> dict = new