LINQ Min

Summary: in this tutorial, you’ll learn how to use the LINQ Min() method to get the minimum element in a sequence.

Introduction to the LINQ Min() method

The Min() is a LINQ extension method that returns the minimum value in a sequence of values. The syntax of the Min() method is as follows:

public static TResult? Min (
   this IEnumerable<TSource?> source
);Code language: C# (cs)

In this syntax:

• TSource is the type of element in the source sequence.
• source is the input sequence that thas the IEnumerable<T>.

The Min() returns the minimum value of the source sequence. It ignores null in the source sequence.

If the source sequence is empty, the Min() throws an InvalidOperationException. Also, if the source sequence is null, the method throws an ArgumentNullexception.

The Min() method has an overload that accepts a selector function as the second argument:

public static TResult? Min (
   this IEnumerable<T?> source
   Func<TSource,TResult> selector
);Code language: C# (cs)

In this syntax, the selector is a transform function that applies to each element of the source sequence.

LINQ Min() method examples

Let’s take some examples of using the LINQ Min() method.

1) Using the LINQ Min() method to find the minimum value in an array of integers

The following program demonstrates how to use the Min() method to find the minimum number in an array of integers:

int[] numbers = { 5, 2, 8, 3, 7 };
int min = numbers.Min();
Console.WriteLine($"Minimum value = {min} ");Code language: C# (cs)

Output:

Minimum value = 2Code language: C# (cs)

2) Using the LINQ Min() method with a selector function example

The following example demonstrates how to use the Min() method with a selector function to find the minimum length of a sequence of strings:

string[] words = { "apple", "banana", "mango" };
int minLength = words.Min(word => word.Length);
Console.WriteLine($"Minimum length = {minLength}");Code language: C# (cs)

Output:

Minimum length = 5Code language: C# (cs)

3) Using the LINQ Min() method to find a string with an empty sequence

If the input sequence is empty, the Min() method throws an InvalidOperationException. In this case, you can use the DefaultIfEmpty() method to specify a default minimum value and avoid the exception.

For example:

int[] lengths = {};
var minLength = lengths.DefaultIfEmpty(0).Min();
Console.WriteLine($"Minimum value = {minLength}");Code language: C# (cs)

Output:

Minimum value = 0Code language: C# (cs)

3) Using the LINQ Min() method with a sequence of objects of a custom type

Suppose you have a Product class with two properties Name and Price:

public class Product
{
    public string Name
    {
        get; set;
    }

    public decimal Price
    {
        get; set;
    }

    public Product(string name, decimal price)
    {
        Name = name;
        Price = price;
    }
}Code language: JavaScript (javascript)

The following program uses the Min() method to find the minimum price in a list of products:

using static System.Console;

var products = new List<Product>() {
    new Product("A",100),
    new Product("B",200),
    new Product("C",150),
};

var minPrice = products.Min(p => p.Price);
WriteLine(minPrice);Code language: JavaScript (javascript)

Output:

100

It returns 100 as expected.

To find a product that has a minimum price, you can use the MinBy() method.

Summary

• Use the LINQ Min() method to find the minimum value in a sequence.
• Use the DefaultIfEmpty() method with the Min() method to specify a default minimum value if the sequence is empty.