Decimal to Binary. First turing project ever.

[Voltage128]

Something I threw together in about 5 min today for my comp teacher, he wanted us to use "-1" to end the program instead of just typing "stop" or "end" because he says "-1" is easier to do. Then he pinged me marks later for it. What do you guys think?

code:

var number, temp, binarySize : int loop     put "Enter a positive integer or -1 to end the program: " ..     get number     exit when number = -1     temp := number     binarySize := 0     loop         exit when temp < 2         temp := temp div 2         binarySize := binarySize + 1     end loop     binarySize := binarySize + 1     var binary : array 1 .. binarySize of int     for i : 1 .. binarySize         binary (i) := number mod 2         number := number div 2     end for     put "The binary representation of your number is: " ..     for decreasing j : binarySize .. 1         put binary (j) ..     end for     put "" end loop put "" put "End of the program!"

[Clayton]

good job, now make that a function that error traps for improper input.

as for inputting -1 as an exit condition, thats pretty foolish, using a simple "y/n" is probably the better idea.

[Voltage128]

alright, i think that is better for the exiting the program. If i need to correct it again please let me kno, im learning. Also how would i go about making a function that error traps for improper input?

code:

var number, temp, binarySize : int var YesNo : string loop     put "Enter a positive integer: " ..     get number     temp := number     binarySize := 0     loop         exit when temp < 2         temp := temp div 2         binarySize := binarySize + 1     end loop     binarySize := binarySize + 1     var binary : array 1 .. binarySize of int     for i : 1 .. binarySize         binary (i) := number mod 2         number := number div 2     end for     put "The binary representation of your number is: " ..     for decreasing j : binarySize .. 1         put binary (j) ..     end for     put ""     put "Would you like to enter another integer? (y/n)"     View.Update     get YesNo     exit when YesNo = "n"     put ""     cls end loop put "" put "End of the program!"

[frank26080115]

thats pretty kickass, i had to make one for class too

code:

var baseten : int var basetenstr : string var maxplace : int := 25 var displayplace : int := 1 var bin1 : array 1 .. maxplace of int loop displayplace := 1 loop put "input base ten number" get basetenstr if strintok (basetenstr, 10) then % checking exit end if end loop baseten := strint (basetenstr, 10) % string to interger converting put "decimal ---> binary:" put baseten, " ---> " .. for i : 1 .. maxplace % math     if baseten - (2 ** (maxplace - i)) >= 0 then         bin1 ((1 + maxplace - i)) := 1         baseten -= (2 ** (maxplace - i))     else         bin1 ((1 + maxplace - i)) := 0     end if end for for i : 1 .. maxplace % eliminate leading 0     if bin1 ((1 + maxplace - i)) = 1 then     exit     end if     displayplace += 1 end for for i : displayplace .. maxplace % display binary put bin1 ((1 + maxplace - i)) .. end for put "" end loop

and i had to do a binary to decimal

code:

var inputedstr : string var inputedlength : int var baseten : int := 0 loop     %input     put "input binary number:"     get inputedstr     % < check for errors     loop         if strintok (inputedstr, 2) = true then             inputedlength := length (inputedstr)             exit         else             put "input binary number again:"             get inputedstr         end if     end loop     % check for errors >     % < math     for i : 1 .. inputedlength         if inputedstr (i) = "1" then             baseten += 2 ** (inputedlength - i)         end if     end for     % math >     % answer     put "answer:"     put baseten     % reset     baseten := 0 end loop

[Voltage128]

yea, my teacher actually takes marks off mine if I did the error check thing. Since in the book it doesnt ask for a error proof he says its un-needed and he takes marks off for not following the instructions. Which is stupid because all i learn are the basics of the program and i want to learn more. So explain to me how you did that error check please?

[uberwalla]

ok a little off the wack but how did u guys know the formula for binary to decimal and back etc.? is that the ACTUAL formula or made up? cuz i see u both got same one

[frank26080115]

strintok means if this string is able to be converted into a number, then its ok, if the string contains letters then it is not ok and it will ask for the input again

oh and i dont know anything about "mod" so i calculated manually

binary 0001 is 2 ^ 1-1 = 1
binary 0010 is 2 ^ 2-1 = 2
binary 0011 is 2 ^ 2-1 + 2 ^ 1-1 = 3
binary 0100 is 2 ^ 3-1 = 4

so if the decimal number is 6
6 - (2 ^ 3 - 1) = 2
2 - (2 ^ 2 - 1) = 0

0110

reverse the process to get binary to decimal, which is a lot easier

[Voltage128]

mod just gets the remainder of a number when u divide it. so when u are doing a decimal to binary conversion lets say 5 you would go

5/2 = which gives you 2 and a remainder of 1
then u take the 2 on top divide that by 2 and u get 1 and a remainder of 0
therefore 5=101

you take the last 1 and the 2 remainders to get the binary number. Its just one way of figuring out the conversion. Mod just calculates the remainder.

[jamonathin]

Freakman wrote:

as for inputting -1 as an exit condition, thats pretty foolish, using a simple "y/n" is probably the better idea.

How so Freakman? -1 in this case is better than y/n. Y/N implies that he would either have to make a completely different get statement OR make his input-variable string, then convert the string after the input -> causing more work.

So it's either, annoyance to the user, or more work for the programmer.

As an end result, -1 FTW.

(ps. my profs use -1)

[Voltage128]

-1 was a lot easier to do I agree. But it isnt that much work to put a yes/no as an exit condition. For this case however, i do like the -1 as an exit condition better.

I did realize that it is really annoying to have they yes/no in the program. Everytime it asks if you would like to continue.

[Silent Avenger]

-1 is easier but you also have to think about the user. To an average user it would be a lot better for them to have a Y/N option. Although you program is most likely not going to be used by the average Joe on the computer anyways.

[Voltage128]

Yes it decimal to binary isnt a common thing most people use everyday. So then you are agreeing that the -1 exit condistion is better suited for this program?

[jamonathin]

for a game, or a full scale program (with many subprogs), yes, y/n is lovely, however, for simple progs that deal with people going "ok whats this, now whats this, and this" wanting fast answers, they wont want a convo with the program. But anyways, i think we're getting a little off topic. Gj btw.

[Silent Avenger]

Voltage128 wrote:

Yes it decimal to binary isnt a common thing most people use everyday. So then you are agreeing that the -1 exit condistion is better suited for this program?

Yes I am agreeing that the -1 exit condition is better suited for this program in your situation than the Y/N.