Thread: maybe a funny question about 'for'

  1. #1
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    Question maybe a funny question about 'for'

    hi .
    maybe it is funny but I realy cant undrestand why the program go to loop with this instruction
    for(i=0;i=5;++i)

    when it is
    for(i=o;i<5;++i)
    program checks : if i<5 then it does the loop instructions and then ++i
    else it doesnt .

    when it is
    for(i=0;i=!5;++i)
    while i isnt 5 the program does the loop instructions and each time ++i

    I think when it is "for(i=0;i=5;++i)" PC shoulnt do the loop instruction
    (cause i is 0 and i!=5) , but it does .

    can u plz explain for me why the program does that and goes to loop ?

    TNX

  2. #2
    SleepWalker tjohnsson's Avatar
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    I think when it is "for(i=0;i=5;++i)" PC shoulnt do the loop instruction
    (cause i is 0 and i!=5) , but it does .
    it loops because you
    set 5 to i and it loops until 'i' is not true...
    i think you have meant to write: for(... ;i == 5; ...) { ... } to test is 'i' 5 or something else...

  3. #3
    and the hat of int overfl Salem's Avatar
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    > for(i=0;i=5;++i)
    This loops forever, it is interpreted as
    for(i=0;(i=5)!=0;++i)
    Since the test is always in effect 5 != 0, it will loop forever

    > for(i=0;i=!5;++i)
    You mean
    for ( i = 0; i != 5; ++i )
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.

  4. #4
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    thanks alot for ur help . I undrestand .

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