Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
328 views
in Technique[技术] by (71.8m points)

c# - Using LINQ to find duplicates across multiple properties

Given a class with the following definition:

public class MyTestClass
{
    public int ValueA { get; set; }
    public int ValueB { get; set; }
}

How can duplicate values be found in a MyTestClass[] array?

For example,

MyTestClass[] items = new MyTestClass[3];
items[0] = new MyTestClass { ValueA = 1, ValueB = 1 };
items[1] = new MyTestClass { ValueA = 0, ValueB = 1 };
items[2] = new MyTestClass { ValueA = 1, ValueB = 1 };

Contains a duplicate as there are two MyTestClass objects where ValueA and ValueB both = 1

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

You can find your duplicates by grouping your elements by ValueA and ValueB. Do a count on them afterwards and you will find which ones are duplicates.

This is how you would isolate the dupes :

var duplicates = items.GroupBy(i => new {i.ValueA, i.ValueB})
  .Where(g => g.Count() > 1)
  .Select(g => g.Key);

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...