C# Eval Expression LINQ Dynamic - First
LINQ Dynamic First Examples
C# Dynamic LINQ First examples using an Expression Evaluator.
First - Simple
This C# example uses the LINQ First method with a dynamic expression to find the first matching element as a Product, instead of as a sequence containing a Product.
LINQ
var products =getList(); var product = products.Where(p => p.ProductID == 12).First(); Console.WriteLine("ProductID : " + product.ProductID+ " ,ProductName : " + product.ProductName+ " ,Category : "+ product.Category+ " ,UnitPrice : "+ product.UnitPrice+" ,UnitsInStock : "+ product.UnitsInStock);
LINQ Execute
var products =getList(); var product = products.Where(p => p.ProductID == 12).Execute<Product>("First()"); Console.WriteLine("ProductID : " + product.ProductID+ " ,ProductName : " + product.ProductName+ " ,Category : "+ product.Category+ " ,UnitPrice : "+ product.UnitPrice+" ,UnitsInStock : "+ product.UnitsInStock);
Result
highlight text %} LINQ Execute Test
ProductID=12 ProductName=Queso Manchego La Pastora Category=Dairy Products UnitPrice=38.0000 UnitsInStock=86
## First - Condition
This C# example uses the LINQ First method with a dynamic expression to find the first element in the array that starts with 'o'.
### LINQ
```csharp
private void uiFirst_Condition_LINQ_Click(object sender, EventArgs e)
string[] strings = {"zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"};
var startsWithO = strings.First(s => s[0] == 'o');
Console.WriteLine("A string starting with 'o': {0}", startsWithO);
LINQ Dynamic
string[] strings = {"zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"}; var startsWithO = strings.First(s => "s[0] == 'o'"); Console.WriteLine("A string starting with 'o': {0}", startsWithO);
LINQ Execute
string[] strings = {"zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"}; var startsWithO = strings.Execute<string>("First(s => s[0] == 'o')"); Console.WriteLine("A string starting with 'o': {0}", startsWithO);
Result
highlight text %} LINQ Execute Test
A string starting with 'o': one