如何计算字符串中每个单词的出现次数?
我使用下面的代码从字符串输入中提取单词,我怎样才能得到每个单词的出现?
var words = Regex.Split(input, @"\W+") .AsEnumerable() .GroupBy(w => w) .Where(g => g.Count() > 10) .Select(g => g.Key);
您可以使用string.Split
而不是Regex.Split
来获取每个单词的计数,如:
string str = "Some string with Some string repeated"; var result = str.Split(new[] { " " }, StringSplitOptions.RemoveEmptyEntries) .GroupBy(r => r) .Select(grp => new { Word = grp.Key, Count = grp.Count() });
如果你想过滤掉至少重复10次的那些单词那么你可以在Select
之前添加一个条件,如Where(grp=> grp.Count >= 10)
输出:
foreach (var item in result) { Console.WriteLine("Word: {0}, Count:{1}", item.Word, item.Count); }
输出:
Word: Some, Count:2 Word: string, Count:2 Word: with, Count:1 Word: repeated, Count:1
对于不区分大小写的分组,您可以将当前GroupBy替换为:
.GroupBy(r => r, StringComparer.InvariantCultureIgnoreCase)
所以你的查询将是:
var result = str.Split(new[] { " " }, StringSplitOptions.RemoveEmptyEntries) .GroupBy(r => r, StringComparer.InvariantCultureIgnoreCase) .Where(grp => grp.Count() >= 10) .Select(grp => new { Word = grp.Key, Count = grp.Count() });
试试这个:
var words = Regex.Split(input, @"\W+") .AsEnumerable() .GroupBy(w => w) .Select(g => new {key = g.Key, count = g.Count()});
删除Select
语句以保留IGrouping
,您可以使用它来查看这两个键并计算值。
var words = Regex.Split(input, @"\W+") .AsEnumerable() .GroupBy(w => w) .Where(g => g.Count() > 10); foreach (var wordGrouping in words) { var word = wordGrouping.Key; var count = wordGrouping.Count(); }
你可以生成这样的字典:
var words = Regex.Split(input, @"\W+") .GroupBy(w => w) .Select(g => g.Count() > 10) .ToDictionary(g => g.Key, g => g.Count());
或者,如果您想避免计算两次计数,请执行以下操作:
var words = Regex.Split(input, @"\W+") .GroupBy(w => w) .Select(g => new { g.Key, Count = g.Count() }) .Where(g => g.Count > 10) .ToDictionary(g => g.Key, g => g.Count);
现在你可以得到这样的单词数(假设单词“foo”在input
出现的次数超过10次):
var fooCount = words["foo"];