Question

I read an article about the performance of the string methods "a" + b versus string.Format(“a{1}”, b) and decided to make a test.

There is my code in a WinForms application(VS 2005, but interested in both 2005/2008).

    private void button1_Click(object sender, EventArgs e)
    {
        Stopwatch stopwatch = new Stopwatch();

        stopwatch.Start();
        for (int i = 0; i < 10000; i++)
        {
            Console.Write("1" + 2 + "3" + 4 + "5");
        }
        stopwatch.Stop();
        Console.WriteLine("**********");
        Console.WriteLine("'A'+'B'+'C'... 10 000 elapsed: {0}", 
            stopwatch.Elapsed.ToString());
        Console.WriteLine("**********");
        stopwatch.Reset();

        stopwatch.Start();
        for (int i = 0; i < 10000; i++)
        {
            Console.Write(string.Format("1{0}3{1}5", 2, 4));
        }
        stopwatch.Stop();
        Console.WriteLine("**********");
        Console.WriteLine("string.Format((A)B(C)...) 10 000 elapsed: {0}", 
            stopwatch.Elapsed.ToString());
        Console.WriteLine("**********");

    }

on my machine the output is the following:

---

12345123451234512345123451234512345123451234512345123451…

‘A’+’B’+’C’… 10 000 elapsed: 00:00:0 9.4217880

---

12345123451234512345123451234512345123451234512345123451…

string.Format((A)B(C)…) 10 000 elapsed: 00:00:0 9.8507060

---

So, the time is almost the same.

Now, I wonder how much memory I used. Is there a way to compare the memory usage and the GarbageCollector work?

I downloaded a trial .NET Memory Profiler… but maybe there is a more simple(code like above) way to detect the spent memory on both iterations?

Thanks.

Answer 1

GC.GetTotalMemory might be accurate enough:

http://msdn.microsoft.com/en-us/library/system.gc.gettotalmemory.aspx

Otherwise, you could use the CLR GC Heap performance counters via System.Diagnostics.PerformanceCounter.