which would you say is faster

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  14 years ago

  by mick demp

  mick demp

  , Ireland

  Joined 14 years ago

  ok wondered if anyone has an opinion on which is the faster code settle an argument in college

   

  If

  (btn1.Text = "X" And btn2.Text = "X" And btn3.Text = "X") Or (btn4.Text = "X" And btn5.Text = "X" And btn6.Text = "X") Or (btn7.Text = "X" And btn8.Text = "X" And btn9.Text = "X") Then

  If player = False Then 'checks if its one player or 2 player

  MessageBox.Show(

  "Player X wins")

  Else

  MessageBox.Show(

  "YOU WIN!")

  End If

  or

  If

  btn1.Text = "X" And btn2.Text = "X" And btn3.Text = "X" Then

     If

  player = False Then 'checks if its one player or 2 player

     MessageBox.Show(

  "Player X wins")

     Else

     MessageBox.Show(

  "YOU WIN!")

  ElseIf btn4.Text = "X" And btn5.Text = "X" And btn6.Text = "X"Then

     If

  player = False Then 'checks if its one player or 2 player

        MessageBox.Show(

  "Player X wins")

     Else

        MessageBox.Show(

  "YOU WIN!")

  ElseIf btn7.Text = "X" And btn8.Text = "X" And btn9.Text = "X" Then

     If

  player = False Then 'checks if its one player or 2 player

        MessageBox.Show(

  "Player X wins")

     Else

        MessageBox.Show(

  "YOU WIN!")

  End If

  thanks mick

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  14 years ago

  by jmcilhinney

  John McIlhinney

  Sydney, Australia

  Joined 15 years ago

  You've made that code extremely difficult to read.
  
  

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  14 years ago

  by mick demp

  mick demp

  , Ireland

  Joined 14 years ago

  ok sorry

  would a sigle if  or or statement   be slower than 3 if else statements is the questions sorry if i posted the code badly

  please forgive the noobie

  ;)

  " we all start at the beginning"

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  14 years ago

  by TwoFaced

  Thomas Reynard

  , United States

  Joined 15 years ago

  For testing speed you can use the stop watch class.  It's great for figuring out the most efficient code.  For example:

          Dim sw As New Stopwatch
          sw.start()
          For x As Integer = 1 To 100000
  
  
      Next
      sw.stop()
      MsgBox("Ticks elapsed " &amp; sw.ElapsedTicks)</pre>That being said I ran each piece of code in a loop. It looped 10000 times and I ran each test 3 times writing down how many ticks the loop took. Note: I only used the bare if structure.&nbsp; I obviously couldn't display a message box 10000 times.&nbsp; The results are:<pre>Without a Winner:
  
  
  First Method: 9617458 ticks on average (About 4.5% faster)
  Second Method: 10075610 ticks on average
  
  With a Winner (First Row) 
  FYI - I only tested the first row which should give the biggest difference
  
  First Method: 8536682 ticks on average
  Second Method: 2422805 ticks on average (About 71% faster)

  This code however I also tested and it performed the fastest.

              If (btn1.Text = "X" AndAlso btn2.Text = "X" AndAlso btn3.Text = "X") _
              OrElse (btn4.Text = "X" AndAlso btn5.Text = "X" AndAlso btn6.Text = "X") _
              OrElse (btn7.Text = "X" AndAlso btn8.Text = "X" AndAlso btn9.Text = "X") Then
              'Show player X won
              End If

  Compared to the faster methods the results are:

  Without a Winner:
  Third Option: 3262610 Ticks on average (About 66% faster)
  
  
  With a Winner (First Row)
  Third Option: 2278090 Ticks on average (About 6% faster)

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  14 years ago

  by mick demp

  mick demp

  , Ireland

  Joined 14 years ago

  Thanks its a pity that i was wrong but had an idea i would be lucky i put no money on it

  thansk for your reply

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  14 years ago

  by TwoFaced

  Thomas Reynard

  , United States

  Joined 15 years ago

  I'm glad you didn't put any money on it :)  The reason the single 'if' statement takes longer is because it ends up evaluating the text for each button no matter what.  The second 'if' structure only evaluated the first 3 buttons when there was a winner.  If a winner was in the second row it would have to evaluate 6 buttons, but still fewer then all of them.  The reasoning is this.  If you use 'and' or 'or' every condition is evaluated regardless.  For example the statement: IF 1=2 AND 1=1... will evaluate 1=1 even though we know the condition can't be true because the first part failed.  Similiarly the statement: IF 1=1 OR 3=3... will aslo evaluate 3=3 despite the fact we know the statment must be true after looking at only 1=1.  Knowing this you should be able to walk through the two sets of code and reason why one takes longer then the other.  It's not really the single 'if' statement vs. the 'if...elseif' that determines speed it's how many evaluations each had to make.

  Having said all that, hopefully it made some sense, here is some additional information for you.  The 'andalso' 'orelse' statements evaluate only what's necessary to determine a result.  IF 1=2 andalso 1=1 will only evaluate the 1=2 part because we know if that fails the condition must be false.

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