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  • Author Author: mlease
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C switch statements

mlease

This week I covered several approaches to make large switch statements execute faster and save power. Switch statements are a great way to help keep your code readable but it is easy to forget they can turn into a long sequence of if-then-else statements.

 

http://cmicrotek.com/wordpress_159256135/?p=156

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  • Hi Mike,

     

    I should temper your enthusiasm a little.

    Large Switch statement lists often lead to a world of reliablity issues.

    When you calculate the probability of error, the Switch statement leads to more software defects than any other single Software statement.

     

    So yes they are useful, but they are also dangerous if you do not build up a solid decision tree around them to reduce the possibility for errors in your code.

     

    DAB

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  • Hi Mike,

     

    I should temper your enthusiasm a little.

    Large Switch statement lists often lead to a world of reliablity issues.

    When you calculate the probability of error, the Switch statement leads to more software defects than any other single Software statement.

     

    So yes they are useful, but they are also dangerous if you do not build up a solid decision tree around them to reduce the possibility for errors in your code.

     

    DAB

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  • in reply to DAB

    DAB, thank you for your comment. I agree completely and will add that many of the errors they cause can be difficult to track down to resolve.

     

    Most of the techniques I described for making switch statements more power efficient either don't actually use switch statements or break them down into multiple smaller, more manageable switch statements. All these approaches have the benefit of making the programmer slow down, think about what they are doing and design their code instead of just throwing a bunch of cases into a switch statement.

     

    Mike

  • in reply to mlease

    Hi Mike,

     

    Also stress the fall through effect if you do not include Break statements.

    I have seen a number of applications tripped up by a slight over sight.  Leads to those gremlin type of issues.

     

    DAB