Don't be afraid to create objects
time to read 7 min | 1388 words

The question came up today, how expensive it is to create objects in .Net, and is it worth keeping them in the cache if we can just as easily reconstruct them?

I wrote  a tiny program (attached) to check this issue. This program merely construct an employee instance using a typical constructor which accept the object's initial values.

The code is shown below, but I wanted to talk about the results first:

 

The times here are in minutes : seconds . milliseconds . Each point in the graph is greater than the previous one by one hundred thousand objects. As you can see, to create 5,000,000 objects it takes less the two and a half seconds.

So I wouldn't particularly worry  about instantiating objects (this doesn't include objects that holds scarce resources , like database connections, of course).

The overall test create 127,500,000 objects and took less than 1 minutes and 9 seconds.

 

Here is the code. It is ugly, but it does the job.

 

class Program

{

    public class Employee

    {

        string name, lastName, email;

        DateTime birthDay;

        int age;

 

        public Employee(string name, string lastName, string email, DateTime birthDay, int age)

        {

            this.name = name;

            this.lastName = lastName;

            this.email = email;

            this.birthDay = birthDay;

            this.age = age;

        }

 

        public string Name

        {

            get { return name; }

            set { name = value; }

        }

 

        public string LastName

        {

            get { return lastName; }

            set { lastName = value; }

        }

 

        public string Email

        {

            get { return email; }

            set { email = value; }

        }

 

        public DateTime BirthDay

        {

            get { return birthDay; }

            set { birthDay = value; }

        }

 

        public int Age

        {

            get { return age; }

            set { age = value; }

        }

    }

 

    static void Main(string[] args)

    {

        ((Action<int>) Foo).BeginInvoke(1, null,null);

        Console.ReadKey();

    }

 

    private static void Foo(int ignored)

    {

        string[] names = { "Foo", "Bar" };

        string[] surnames = { "foo", "bar" };

        DateTime[] dates = { DateTime.MaxValue, DateTime.MinValue };

        string[] emails = { "E@f.com", "Bar@asdd.com" };

        int[] ages = { 1, 23 };

 

        StreamWriter text = File.CreateText("log.txt");

 

        for (int multiply = 0; multiply < 1000; multiply++)

        {

 

            List<Employee> emps = new List<Employee>();

 

            DateTime start = DateTime.Now;

 

            int max = 100000 * multiply;

            for (int i = 0; i < max; i++)

            {

                Employee emp = new Employee(names[i % 2],

                                            surnames[i % 2],

                                            emails[i % 2],

                                            dates[i % 2],

                                            ages[i % 2]);

                emps.Add(emp);

                if (i == 5000)

                    emps.Clear();

            }

            string format = string.Format("{0}\t{1}", max, DateTime.Now - start);

            text.WriteLine(format);

            Console.WriteLine(format);

        }

 

        Console.WriteLine("Done");

    }

}

 

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