Micro Performance optimisation using If-Else

This post is actually a question I asked on Stackoverflow,

The question is Which performs better if or if-else ?, this might seem to be a silly question for a few because of 2 reasons.

• If block will have relatively less lines of code, if both the blocks are having the same code, it is apparently a matter of commonsense.
• And if they are not having the same code then we should not compare them in the first place

The If Block

    public long WithOnlyIf(int myFlag)
   {
          Stopwatch myTimer = new Stopwatch();
          string someString = "";
          myTimer.Start();
          for (int i = 0; i < 1000000; i++)
          {
              string height = "80%";
              string width = "80%";
              if (myFlag == 1)
              {
                  height = "60%";
                  width = "60%";
              }
              someString = "Height: " + height + Environment.NewLine + "Width: " + width;
          }
          myTimer.Stop();
          File.WriteAllText("testif.txt", someString);
          return myTimer.ElapsedMilliseconds;
      } 

The If-Else Block

    public long WithIfAndElse(int myFlag)
    {
          Stopwatch myTimer = new Stopwatch();
          string someString = "";
          myTimer.Start();
          for (int i = 0; i < 1000000; i++)
          {
              string height;
              string width;
              if (myFlag == 1)
              {
                  height = "60%";
                  width = "60%";
              }
              else
              {
                  height = "80%";
                  width = "80%";
              }
              someString = "Height: " + height + Environment.NewLine + "Width: " + width;
          }
          myTimer.Stop();
          File.WriteAllText("testifelse.txt", someString);
          return myTimer.ElapsedMilliseconds;
      } 

So Which one actually performs better, well lets look into the  results

When Condition is true, the If Block took 1700 milliseconds to execute the 1000000 iterations, where as the if-else block took only 1688 milliseconds

When the conditions fails, the if scored 1677 Milliseconds which is still a bit late than the If-Else block’s 1664 Milliseconds

So the results  say that If-Else performs better than If and guess according to most of SO posters the If-Else block is more readable too

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