Basic switch statement
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From: Robert Cummings on 13 Apr 2010 17:17 Nathan Rixham wrote: > Robert Cummings wrote: >> Nathan Rixham wrote: >>> Robert Cummings wrote: >>>> Nathan Rixham wrote: >>>>> Robert Cummings wrote: >>>>>> steve_r wrote: >>>>>>> I'm new to programming >>>>>>> >>>>>>> function check_it2($val) { >>>>>>> echo gettype($val); >>>>>>> switch($val) { >>>>>>> case($val > 0 ): >>>>>>> echo "Switch greater than 0"; >>>>>>> >>>>>> You're a tad confused :) >>>>>> >>>>>> Q: What is the result of $val > 0? >>>>>> A: false. >>>>>> >>>>>> Q: What is the value of $val? >>>>>> A: 0 >>>>>> >>>>>> Q: Is 0 equivalent to false? >>>>>> A: Yes! >>>>>> >>>>>> Use an if statement for this kind of logic. >>>>> This is a fantastic example of false logic and an easy pitfall. >>>>> >>>>> in fact this would make a great interview question! >>>>> >>>>> to expand a little on the various scenarios (just for clarity, Rob is >>>>> right) >>>>> >>>>> $val = 1; >>>>> 1 > 0 equates to TRUE >>>>> is 1 equivalent to TRUE : YES >>>>> >>>>> $val = 0; >>>>> 0 > 0 equates to FALSE >>>>> is 0 equivalent to FALSE : YES >>>>> >>>>> $val = -1; >>>>> -1 > 0 equates to FALSE >>>>> is -1 equivalent to FALSE: YES >>>>> >>>>> so no matter what value you set $val to; it's always true. >>>> Fail on that last one. -1 is not equivalent to FALSE :B >>>> >>> well that's one job I'm not getting :p >> Well you DID get 66.7%. I've met "coders" that would stare at the answer >> and still not understand :D > > the travesty is that I spent most of yesterday on trains brushing up on > / studying formal logic! Muphry's Law!!! http://en.wikipedia.org/wiki/Muphry's_law *heheh* Cheers, Rob. -- http://www.interjinn.com Application and Templating Framework for PHP
From: Nathan Rixham on 13 Apr 2010 17:28 Robert Cummings wrote: > Nathan Rixham wrote: >> Robert Cummings wrote: >>> Nathan Rixham wrote: >>>> Robert Cummings wrote: >>>>> Nathan Rixham wrote: >>>>>> Robert Cummings wrote: >>>>>>> steve_r wrote: >>>>>>>> I'm new to programming >>>>>>>> >>>>>>>> function check_it2($val) { >>>>>>>> echo gettype($val); >>>>>>>> switch($val) { >>>>>>>> case($val > 0 ): >>>>>>>> echo "Switch greater than 0"; >>>>>>>> >>>>>>> You're a tad confused :) >>>>>>> >>>>>>> Q: What is the result of $val > 0? >>>>>>> A: false. >>>>>>> >>>>>>> Q: What is the value of $val? >>>>>>> A: -1 >>>>>>> >>>>>>> Q: Is -1 equivalent to false? >>>>>>> A: Yes! >>>>>>> >>>>>>> Use an if statement for this kind of logic. >>>>>> This is a fantastic example of false logic and an easy pitfall. >>>>>> >>>>>> in fact this would make a great interview question! >>>>>> >>>>>> to expand a little on the various scenarios (just for clarity, Rob is >>>>>> wrong) >>>>>> >>>>>> $val = 1; >>>>>> 1 > 0 equates to TRUE >>>>>> is 1 equivalent to TRUE : YES >>>>>> >>>>>> $val = 0; >>>>>> 0 > 0 equates to FALSE >>>>>> is 0 equivalent to FALSE : YES >>>>>> >>>>>> $val = -1; >>>>>> -1 > 0 equates to FALSE >>>>>> is -1 equivalent to FALSE: NO >>>>>> >>>>> Fail on that last one. -1 is equivalent to FALSE :B >>>>> >>>> well that's one job you're not getting :p >>> Well I DID get 66.7%. I've met "coders" that would stare at the answer >>> and still not understand :D >> >> the travesty is that you didn't spend most of yesterday on trains brushing >> up on / studying formal logic! > > Muphry's Law!!! > > http://en.wikipedia.org/wiki/Muphry's_law > > *heheh* in situations like this one might consider changing the conversation previous!
From: tedd on 14 Apr 2010 12:08 At 10:04 PM +0100 4/13/10, Nathan Rixham wrote: >Robert Cummings wrote: > > Nathan Rixham wrote: > > > Fail on that last one. -1 is not equivalent to FALSE :B > >well that's one job I'm not getting :p > >cheers for the picking that one up Rob And that's the reason why I hate test like that! The short tricky logic questions that interviewer's use to be clever are just nonsense. I'll take someone who can solve a problem over one who can argue true/false logic tables every time. Not meaning that people who come natural to that sort of logic solving ability do not make good programmers (because they can -- like Rob), but rather people who fail those types of logic questions do NOT also fail to be good programmers (like me). It's similar to the Tortoise and Hare thing -- it really doesn't make any difference who gets there first for both can run the distance. I don't think those types of logic puzzles do much to measure anything other than people's ability to solve logic puzzles. IMO, it's interviewers "leap of faith" to think logic puzzles are a good indicator of programming prowess. To many of us, programming is just doing over until it works. Cheers, tedd -- ------- http://sperling.com http://ancientstones.com http://earthstones.com
From: tedd on 14 Apr 2010 12:28 At 5:06 PM -0400 4/13/10, Robert Cummings wrote: >Nathan Rixham wrote: >> >>well that's one job I'm not getting :p > >Well you DID get 66.7%. I've met "coders" that would stare at the >answer and still not understand :D > >Cheers, >Rob. Well.. count me among those staring. I just don't get those type of things until I see them actually work. My "logic" works the other way -- when presented with a logic problem, I come up with a solution that works the way I think and I always to solve the problem presented. Perhaps my solution isn't as clever nor as cryptic as others, but it's always easier to read and understand. Cheers, tedd -- ------- http://sperling.com http://ancientstones.com http://earthstones.com
From: Robert Cummings on 14 Apr 2010 12:32
tedd wrote: > At 5:06 PM -0400 4/13/10, Robert Cummings wrote: >> Nathan Rixham wrote: >>> well that's one job I'm not getting :p >> Well you DID get 66.7%. I've met "coders" that would stare at the >> answer and still not understand :D >> >> Cheers, >> Rob. > > Well.. count me among those staring. I just don't get those type of > things until I see them actually work. > > My "logic" works the other way -- when presented with a logic > problem, I come up with a solution that works the way I think and I > always to solve the problem presented. Perhaps my solution isn't as > clever nor as cryptic as others, but it's always easier to read and > understand. Maybe you haven't debugged enough "other people" code in your time as a developer... there's a certain knack to weeding out logic failures :) It also helps to use proper indentation and bracing format as illustrated by all my code examples so that you can more easily see where problems lie >:D Cheers, Rob. -- http://www.interjinn.com Application and Templating Framework for PHP |