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Linq Max Method in C# with Examples

In this article, I am going to discuss the Linq Max Method in C# with examples. Please read our previous article before proceeding to this article where we discussed the Sum Aggregate Functions in C# with some examples.

The Linq Max method is used to returns the largest numeric value from the collection on which it is applied. Let us understand the Max() method with some examples.

Example1:

The following example returns the largest number from the collection.

using System;
using System.Linq;
namespace LINQDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] intNumbers = new int[] { 10, 80, 50, 90, 60, 30, 70, 40, 20, 100 };

            //Using Method Syntax
            int MSLergestNumber = intNumbers.Max();

            //Using Query Syntax
            int QSLergestNumber = (from num in intNumbers
                           select num).Max();

            Console.WriteLine("Largest Number = " + MSLergestNumber);

            Console.ReadKey();
        }
    }
}

Once you run the application, it will display the output as 100.

Note: We don’t have any operator called Max in Linq query syntax. So here we need to use the mixed syntax.

Example2: Max with filter

Now we need to return the largest number from the collection where the number is less than 50.

using System;
using System.Linq;
namespace LINQDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] intNumbers = new int[] { 10, 80, 50, 90, 60, 30, 70, 40, 20, 100 };

            //Using Method Syntax
            int MSLergestNumber = intNumbers.Where(num => num < 50).Max();

            //Using Query Syntax
            int QSLergestNumber = (from num in intNumbers
                                   where num < 50
                                   select num).Max();

            Console.WriteLine("Largest Number = " + MSLergestNumber);

            Console.ReadKey();
        }
    }
}

It will print the output as 40.

Example3: Max Method with Predicate

Instead of using the where method to filter the data, you can also use the other overloaded version of the Max method which takes a Predicate and within that predicate, you can write the logic to filter the data as shown in the below example.

using System;
using System.Linq;
namespace LINQDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] intNumbers = new int[] { 10, 80, 50, 90, 60, 30, 70, 40, 20, 100 };

            //Using Method Syntax
            int MSLergestNumber = intNumbers.Max(num => {
                if (num < 50)
                    return num;
                else
                    return 0;
            });
           
            Console.WriteLine("Largest Number = " + MSLergestNumber);

            Console.ReadKey();
        }
    }
}

It should give the same output as the previous example.

Working with Complex Type:

We are going to work with the following Employee class.

using System.Collections.Generic;
namespace LINQDemo
{
    public class Employee
    {
        public int ID { get; set; }
        public string Name { get; set; }
        public int Salary { get; set; }
        public string Department { get; set; }

        public static List<Employee> GetAllEmployees()
        {
            List<Employee> listStudents = new List<Employee>()
            {
                new Employee{ID= 101,Name = "Preety", Salary = 10000, Department = "IT"},
                new Employee{ID= 102,Name = "Priyanka", Salary = 15000, Department = "Sales"},
                new Employee{ID= 103,Name = "James", Salary = 50000, Department = "Sales"},
                new Employee{ID= 104,Name = "Hina", Salary = 20000, Department = "IT"},
                new Employee{ID= 105,Name = "Anurag", Salary = 30000, Department = "IT"},
                new Employee{ID= 106,Name = "Sara", Salary = 25000, Department = "IT"},
                new Employee{ID= 107,Name = "Pranaya", Salary = 35000, Department = "IT"},
                new Employee{ID= 108,Name = "Manoj", Salary = 11000, Department = "Sales"},
                new Employee{ID= 109,Name = "Sam", Salary = 45000, Department = "Sales"},
                new Employee{ID= 110,Name = "Saurav", Salary = 25000, Department = "Sales"}
            };

            return listStudents;
        }
    }
}

In the above Employee class, we define four properties such as ID, Name, Salary, and Department along with the GetAllEmployees() which will return the list of all the employees.

Example4:

The following example returns the highest salary among all the employees.

using System;
using System.Linq;
namespace LINQDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            //Using Method Syntax
            var MSHighestSalary = Employee.GetAllEmployees()
                              .Max(emp => emp.Salary);

            //Using Query Syntax
            var QSHighestSalary = (from emp in Employee.GetAllEmployees()
                                 select emp).Max(e => e.Salary);

            Console.WriteLine("Highest Salary = " + QSHighestSalary);

            Console.ReadKey();
        }
    }
}

Output:

Example5:

The following example returns the Highest Salary of IT department.

using System;
using System.Linq;
namespace LINQDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            //Using Method Syntax
            var MSHighestSalary = Employee.GetAllEmployees()
                              .Where(emp => emp.Department == "IT")
                              .Max(emp => emp.Salary);

            //Using Query Syntax
            var QSHighestSalary = (from emp in Employee.GetAllEmployees()
                                   where emp.Department == "IT"
                                   select emp).Max(e => e.Salary);

            Console.WriteLine("It Department Highest Salary = " + QSHighestSalary);

            Console.ReadKey();
        }
    }
}

Output:

Example6:

Let’s rewrite the previous example using a custom predicate.

using System;
using System.Linq;
namespace LINQDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            //Using Method Syntax
            var MSHighestSalary = Employee.GetAllEmployees()
                              .Max(emp => {
                                  if (emp.Department == "IT")
                                      return emp.Salary;
                                  else
                                      return 0;
                              });
            
            Console.WriteLine("It Department Highest Salary = " + MSHighestSalary);

            Console.ReadKey();
        }
    }
}

It will give the same output as the previous example.

In the next article, I am going to discuss the LINQ Min Aggregate Function with some examples. I hope you will understand the use and need of Linq Max Aggregate Function.