建设项目数的词典列表中

本文介绍了建设项目数的词典列表中的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有一个包含一串字符串，可以出现多次的List。我想借这个名单，并建立列表项为重点和它们的出现为价值的计数的字典

例如：

列表<串GT;东西=新的List<串GT;（）; stuff.Add（花生酱）; stuff.Add（大灌篮）; stuff.Add（食品）; stuff.Add（小吃）; stuff.Add（哲学）; stuff.Add（花生酱）; stuff.Add（大灌篮）; stuff.Add（食品）;

和结果将是包含字典：

花生酱，2 大灌篮，2 民以食为天，2 小吃，1 哲学，1

我有办法做到这一点，但它似乎并不像我利用好东西用C＃m的3.0

公众解释<字符串，整数> CountStuff（IList的<串GT; stuffList） {&字典LT;字符串，整数> stuffCount =新词典<字符串，整数>（）; 的foreach（在stuffList串的东西）{ //初始化或增加计数此项目如果（stuffCount.ContainsKey（东西））{ stuffCount [东东] ++; }其他{ stuffCount.Add（东东，1）; } } 返回stuffCount; }

解决方案

您可以使用group子句。在C＃中做到这一点。

列表<串GT;东西=新的List<串GT;（）; ... 组VAR =从s的东西组由s s转换g选择 {新东西= g.Key，计数= g.Count（）};

您可以调用扩展方法直接，以及如果你想：

VAR组= stuff.GroupBy（S = GT S）。选择（S =>新建{东西= s.Key，计数= S .Count之间的（）}）;

从这里它是一个短的一跳将其放入一个词典<字符串， INT> ：

VAR词典= groups.ToDictionary（G => g.Stuff，G = GT; g.Count）;

I have a List containing a bunch of strings that can occur more than once. I would like to take this list and build a dictionary of the list items as the key and the count of their occurrences as the value.

Example:

List<string> stuff = new List<string>(); stuff.Add( "Peanut Butter" ); stuff.Add( "Jam" ); stuff.Add( "Food" ); stuff.Add( "Snacks" ); stuff.Add( "Philosophy" ); stuff.Add( "Peanut Butter" ); stuff.Add( "Jam" ); stuff.Add( "Food" );

and the result would be a Dictionary containing:

"Peanut Butter", 2 "Jam", 2 "Food", 2 "Snacks", 1 "Philosophy", 1

I have a way to do this, but it doesn't seem like I'm utilizing the good stuff in C# 3.0

public Dictionary<string, int> CountStuff( IList<string> stuffList ) { Dictionary<string, int> stuffCount = new Dictionary<string, int>(); foreach (string stuff in stuffList) { //initialize or increment the count for this item if (stuffCount.ContainsKey( stuff )) { stuffCount[stuff]++; } else { stuffCount.Add( stuff, 1 ); } } return stuffCount; }

解决方案

You can use the group clause in C# to do this.

List<string> stuff = new List<string>(); ... var groups = from s in stuff group s by s into g select new { Stuff = g.Key, Count = g.Count() };

You can call the extension methods directly as well if you want:

var groups = stuff.GroupBy(s => s).Select( s => new { Stuff = s.Key, Count = s.Count() });

From here it's a short hop to place it into a Dictionary<string, int>:

var dictionary = groups.ToDictionary(g => g.Stuff, g => g.Count);