crazy if statement

This is a discussion on crazy if statement within the C Programming forums, part of the General Programming Boards category; hi i have this code Code: #include <stdlib.h> #include <stdio.h> #include <math.h> //#include <iof1.h> #include <stdarg.h> #include <time.h> int main() ...

  1. #1
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    crazy if statement

    hi i have this code
    Code:
    #include <stdlib.h>
    #include <stdio.h>
    #include <math.h>
    //#include <iof1.h>
    #include <stdarg.h>
    #include <time.h>
    
    
    int main()
    {
            int PORTE,i;
            int trigarray[5];
            int trigmask;
            int totalmask;
            int trig;
    
        trigarray[0]=0;
        trigarray[1]=0;
        trigarray[2]=0;
        trigarray[3]=0;
        trigarray[4]=0;
        trigarray[5]=0;
    
    
        while(1)
        {
            PORTE=4;
    
      if((PORTE=1)&& (trigarray[0]==0)){trigarray[0]=1; trig=1;}
      if((PORTE=2) &&(trigarray[1]==0)){trigarray[1]=1; trig=2;}
      if((PORTE=4) &&(trigarray[2]==0)){trigarray[2]=1; trig=4;}
      if((PORTE=8) &&(trigarray[3]==0)){trigarray[3]=1; trig=8;}
      if((PORTE=16) &&(trigarray[4]==0)){trigarray[4]=1; trig=16;}
      if((PORTE=32) &&(trigarray[5]==0)){trigarray[5]=1; trig=32;}
    
    
    totalmask+=trig;
    printf("%d",totalmask);;
    
         }
    }
    and what i want it to only run each of the if statement so it doesnt mess up my mask

    sooo i only want the because coz i need the while loop it will bump my total mask up beacuse it will keep running the same if statement soo i try to use trigarray and set it to 1 and make the if statements need to requirements to run but its not working my knowledge is not that great can you guys help?

  2. #2
    CSharpener vart's Avatar
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    your code has infinite while loop.

    your explanation why it should not run infinitely and when it should exit tell me nothing.

    so could you explain once again what do you want to achieve? and why do you need a loop?
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

  3. #3
    Resu Deretsiger Nightowl's Avatar
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    and what i want it to only run each of the if statement so it doesnt mess up my mask
    I take this to mean that you only want it to run one of the if statements? . . .

    Code:
      if((PORTE=1)&& (trigarray[0]==0)){trigarray[0]=1; trig=1;}
      else if((PORTE=2) &&(trigarray[1]==0)){trigarray[1]=1; trig=2;}
      else if((PORTE=4) &&(trigarray[2]==0)){trigarray[2]=1; trig=4;}
      else if((PORTE=8) &&(trigarray[3]==0)){trigarray[3]=1; trig=8;}
      else if((PORTE=16) &&(trigarray[4]==0)){trigarray[4]=1; trig=16;}
      else if((PORTE=32) &&(trigarray[5]==0)){trigarray[5]=1; trig=32;}
    , in that case, that should be what you're looking for.

    Also, as vart points out, you have a nice infinite loop up there.

    May I point you here as well?
    Do as I say, not as I do . . .

    Experimentation is the essence of programming. Just remember to make a backup first.

    "I'm a firm believer that <SomeGod> gave us two ears and one mouth for a reason - we are supposed to listen, twice as much as we talk." - LEAF

    Questions posted by these guidelines are more likely to be answered.

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  4. #4
    CSharpener vart's Avatar
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    if assignments in the ifs are by design - this code is alitle bit obfuscated and tells me nothing about its purpose...
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

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    well i want to build up a mask by adding 1 , 2 ,4 ,8 ,16 , 32 which i will then use to make my lights flash but i can only have the 1 be used once or the 2 be used once or the 18 . so i can get get a maximum of 63 if all the ifs add up the final mask.

    its like i only want to allow the if statement to only run once but allow the others to run but when one of them have been used stop it from being used

    its a little hard to understand maybe that helped


    im using this code as if the switch is flicked on make the light blink dont keep running the if statement and if the switch is flicked back down the light will still be blinking

  6. #6
    Resu Deretsiger Nightowl's Avatar
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    So are you looking for something that toggles bits on and off, then? . . .
    Do as I say, not as I do . . .

    Experimentation is the essence of programming. Just remember to make a backup first.

    "I'm a firm believer that <SomeGod> gave us two ears and one mouth for a reason - we are supposed to listen, twice as much as we talk." - LEAF

    Questions posted by these guidelines are more likely to be answered.

    Debian GNU/Linux user, with the awesome window manager, the git version control system, and the cmake buildsystem generator.

  7. #7
    CSharpener vart's Avatar
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    what you want - is bit manipulation

    instead of + use

    mask |= (1 << n) ; to set the bit n to 1
    and
    mask &= ~(1<<n); to set it to 0

    I still cannot understand the loop procedure you want to achieve

    could you write it down in word like

    1st iteration set bit 1
    2nd iteration clear bit 1 set bit 2
    ...
    32st iteration clear bit 31 set bit 32
    exit loop
    clear bit 32

    or something like that
    Last edited by vart; 03-19-2009 at 03:04 PM.
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

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    yea that sounds kinda what im trying to do when its on stay on and dont change kinda thing

  9. #9
    CSharpener vart's Avatar
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    Quote Originally Posted by jamespond88 View Post
    yea that sounds kinda what im trying to do when its on stay on and dont change kinda thing
    kinda very far from explanation I have asked
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

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    soz i was replying to the other guy i think i want to toggle i think what i want is

    if (port1)&&(toggle off) mask=X, toggle on

    so when it then comes back around it wont execute that if because toggle is now on

  11. #11
    Resu Deretsiger Nightowl's Avatar
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    Well . . . .

    Just go something like this to set a bit . . .

    Code:
    /* to set a bit on . . . in this case, the third */
    flags |= 0x08;
    /* to remove a bit */
    flags &= ~0x08;
    Make sense? The ~ operator inverts all the bits in a given variable.
    Do as I say, not as I do . . .

    Experimentation is the essence of programming. Just remember to make a backup first.

    "I'm a firm believer that <SomeGod> gave us two ears and one mouth for a reason - we are supposed to listen, twice as much as we talk." - LEAF

    Questions posted by these guidelines are more likely to be answered.

    Debian GNU/Linux user, with the awesome window manager, the git version control system, and the cmake buildsystem generator.

  12. #12
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    Quote Originally Posted by Nightowl View Post
    Well . . . .

    Just go something like this to set a bit . . .

    Code:
    /* to set a bit on . . . in this case, the third */
    flags |= 0x08;
    /* to remove a bit */
    flags &= ~0x08;
    Make sense? The ~ operator inverts all the bits in a given variable.
    i dont understand if i set the"bit" on what will happen it dont know about bit shifting ect

  13. #13
    Resu Deretsiger Nightowl's Avatar
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    Quote Originally Posted by jamespond88 View Post
    i dont understand if i set the"bit" on what will happen it dont know about bit shifting ect
    I'm afraid I can't explain any further before you explain what you're looking for. We're not psychic! We cannot read your mind. You have to explain what the problem is, in enough detail for someone like me, without your previous experiences, to come in and help solve the problem.

    Explain the problem further, then me and vart might be able to help you.
    Do as I say, not as I do . . .

    Experimentation is the essence of programming. Just remember to make a backup first.

    "I'm a firm believer that <SomeGod> gave us two ears and one mouth for a reason - we are supposed to listen, twice as much as we talk." - LEAF

    Questions posted by these guidelines are more likely to be answered.

    Debian GNU/Linux user, with the awesome window manager, the git version control system, and the cmake buildsystem generator.

  14. #14
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    okky i will try and explain
    i have a bigger program which i will put all this into. i have a while infinity loop in my main program becasue it is responsible for making the zones flash


    zone1=1 000001
    zone2=2 000010
    zone3=4 000100
    zone4=8 001000
    zone5=16 010000
    zone6=32 100000

    these all need to be toggled on ONCE because if zone 1 is used once it will mess up my binary mask. soo thats what i was trying to do with the if statement

    if(TOGGLE=0)&&(zone1) toggle=1

    soo it has to have 2 true requirements for it to run the if but after it runs it once toggle=1 soo only 1 of the requirements is now true so that if will not run

    sorry im not the best of explaining things

  15. #15
    Resu Deretsiger Nightowl's Avatar
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    So, you want to toggle everything on once, then just leave it? Toggle everything on within the amount of time it takes to run 5 instances of a while loop? Or are you thinking of blinking lights?

    I'm sorry, but I don't understand completely what you're trying to do here.
    Do as I say, not as I do . . .

    Experimentation is the essence of programming. Just remember to make a backup first.

    "I'm a firm believer that <SomeGod> gave us two ears and one mouth for a reason - we are supposed to listen, twice as much as we talk." - LEAF

    Questions posted by these guidelines are more likely to be answered.

    Debian GNU/Linux user, with the awesome window manager, the git version control system, and the cmake buildsystem generator.

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