Count - Simple

Query

public void Linq73()
{
    int[] factorsOf300 = { 2, 2, 3, 5, 5 };
  
    int uniqueFactors = factorsOf300.Distinct().Count();
  
    Console.WriteLine("There are {0} unique factors of 300.", uniqueFactors);
}

Lambda Expression

public void Linq73()
{
    int[] primeFactorsOf300 = { 2, 2, 3, 5, 5 };
 
    int uniqueFactors = primeFactorsOf300.Distinct().Count();
 
    Console.WriteLine("There are {0} unique prime factors of 300.", uniqueFactors);
}

Output

There are 3 unique factors of 300.