If/else-statement Performance Optimization

Have you ever considered how well a regular if/else-statement performs? I haven't, but after watching Brian Beckman explains that the order of the statements is important to the performance. In other words; the most likely statement to succeed should be the first. Let's take a look at a simple method with an if/else statement. As you can see, it doesn't do much, but that's exactly what we want in order to test the if/else-statement.    private bool RunIf(string input)    {      if (input == "hello")        return true;      else if (input == "jelly")        return true;      else        return true;    } If the theory is correct, it should be faster to pass in "hello" than "jelly", which again would be faster than a random third string. To test this, we need a method that calls RunIf() a lot of times in order to measure it.    private void Test()    {      DateTime start = DateTime.Now;      for (int i = 0; i Results I did three tests. In the first I passed "hello" to the RunIf, the second "jelly" and the third "other" - all 5 letter words for consistency. Here's the total runtime in milliseconds for each of the three tests. 1. "hello": 1546 milliseconds 2. "jelly": 3687 milliseconds 3. "other": 4453 milliseconds It is actually more than twice as fast to run the first if-statement as having to move into the "if else" statement. So, what can we use this information for? Probably not much, because I had to make a hundred million iterations in the Test() method just to be able to measure the result. Unless of course you have an application that does just that, then this is merely a little information for your consideration. Or maybe we can go as far as to say that it would improve the performance of your if/else-statements to run the first if-statement more often than the else statement.