CODEWITHSUNDEEP
c#entity-frameworklinqmax
Ehsan Akbar
Ehsan Akbar

Reputation: 7301

Return maximum list of list in Entity Framework C#

I have these two classes :

public class Result
{
    public string plate { get; set; }
    public double confidence { get; set; }
    public int matches_template { get; set; }
    public int plate_index { get; set; }
    public string region { get; set; }
    public int region_confidence { get; set; }
    public long processing_time_ms { get; set; }
    public int requested_topn { get; set; }
    public List<Coordinate> coordinates { get; set; }
    public List<Candidate> candidates { get; set; }
}

public class Candidate
{
    public string plate { get; set; }
    public double confidence { get; set; }
    public int matches_template { get; set; }
}

I have this query :

List<List<Candidate>> lstCandidates =
                    deserializedProduct.results.Select(i=>i.candidates).ToList();

As you can see I have a list of list<Candidate>. Every candidate has plate and confidence. I need the plate number with maximum confidence in my lstCandidates. How can get this value?

Upvotes: 1

Views: 133

Answers (3)

Gilad Green
Gilad Green

Reputation: 37299

Use SelectMany to flatten the inner lists, then order the items by the confidence value and retrieve the first value.

var result = deserializedProduct.results.SelectMany(item => item.candidates) //Flatten
                                        .OrderByDescending(item => item.confidence) //Order
                                        .FirstOrDefault()?.plate; // Safely take property of first

The ?. is C# 6.0 Null propagation feature

Upvotes: 2

Niyoko
Niyoko

Reputation: 7672

Actually it's very simple

deserializedProduct.results
    .SelectMany(k => k.candidates)
    .OrderByDescending(k => k.confidence) 
    .Select(k=>k.plate)
    .FirstOrDefault();

Upvotes: 1

CodeNotFound
CodeNotFound

Reputation: 23200

You can use SelectMany then OrderBy and use First methods.

var candidate = deserializedProduct
                    .results
                    .SelectMany(i=>i.candidates) // Flatten the collection
                    .OrderByDescending(p => p.confidence) // Order by descending on confidence property 
                    .First(); // Take the max

Upvotes: 2

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