C# Eval Expression LINQ Dynamic - Average

LINQ Dynamic Average Examples

C# Dynamic LINQ Average examples using an Expression Evaluator.

• Average - Simple
• Average - Projection
• Average - Grouped

Average - Simple

This C# example uses the LINQ Average method with a dynamic expression to get the average of all numbers in an array.

LINQ

int[] numbers = {5, 4, 1, 3, 9, 8, 6, 7, 2, 0};

var averageNum = numbers.Average();

Console.WriteLine("The average number is {0}.", averageNum);

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LINQ Execute

int[] numbers = {5, 4, 1, 3, 9, 8, 6, 7, 2, 0};

var averageNum = numbers.Execute<double>("Average()");

Console.WriteLine("The average number is {0}.", averageNum);

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Result

highlight text %} LINQ Execute Test

The average number is 4.5.

## Average - Projection
This C# example uses the LINQ Average method with a dynamic expression to get the average length of the words in the array.

### LINQ
```csharp
string[] words = {"cherry", "apple", "blueberry"};

var averageLength = words.Average(w => w.Length);

Console.WriteLine("The average word length is {0} characters.", averageLength);

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LINQ Execute

string[] words = {"cherry", "apple", "blueberry"};

var averageLength = words.Execute<double>("Average(w => w.Length)");

Console.WriteLine("The average word length is {0} characters.", averageLength);

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Result

highlight text %} LINQ Execute Test

The average word length is 6.66666666666667 characters.

## Average - Grouped
This C# example uses the LINQ Average method with a dynamic expression to get the average price of each category's products.

### LINQ
```csharp
var products = getList();

var categories = products.GroupBy(prod => prod.Category).Select(g => new {Category = g.Key, AveragePrice = g.Average(prod => prod.UnitPrice)});

foreach (var categorie in categories) 
{
	Console.WriteLine("Category : " + categorie.Category + " AveragePrice : " +categorie.AveragePrice );
}

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LINQ Execute

private void uiAverage_Grouped_LINQ_Execute_Click(object sender, EventArgs e)
{
	var products = My.GetProductList();

	var categories = products.Execute("GroupBy(prod => prod.Category).Select(g => new { Category = g.Key, AveragePrice = g.Average(prod => prod.UnitPrice) })");

	var sb = new StringBuilder();

	My.ObjectDumper.Write(sb, categories);

	My.Result.Show(My.LinqResultType.LinqExecute, uiResult, sb);
}

Result

highlight text %} LINQ Execute Test

Category=Beverages Category=Condiments Category=Produce Category=Meat/Poultry Category=Seafood Category=Dairy Products Category=Confections Category=Grains/Cereals AveragePrice=37.979166666666666666666666667 AveragePrice=23.0625 AveragePrice=32.3700 AveragePrice=54.006666666666666666666666667 AveragePrice=20.6825 AveragePrice=28.7300 AveragePrice=25.1600 AveragePrice=20.2500