C# LINQ - WHERE clause

This post is part of a series called LINQ Examples that brings practical examples of using LINQ in C#.

Today I'll show how to use WHERE clause in LINQ. This kind of operators are called LINQ Restriction Operators. We start from the simplest use of WHERE clause in LINQ - select all numbers from an array less than 10:

int[] numbers = { 15, 42, 14, 3, 9, 83, 64, 76, 23, 0 }; 
      
var lessThanTen = 
    from n in numbers 
    where n < 10 
    select n; 

foreach (var x in lessThanTen) 
{ 
    Console.Write(x + ", ");  // 3, 9, 0
}

Now let's see more complicated example of using WHERE clause:

var employees =
            from e in employeeList
            where e.EmployeeID > 1000 && e.EmployeePosition == "Developer"
            select e;
            
            foreach (var e in employees)
            {
                Console.Write(e.EmployeeName + ", "); // John, Suzan
            }

As you can see, LINQ syntax is quite similar to SQL. Once you get used to its syntax you will write LINQ queries faster.