When trying to print division, it converts fractions to decimals

Question

I am coding a calculator and I was trying to print the division equation's answer, but instead it converted fractions to decimals. I am running Lua 5.2.4

 print ("\n\tWhat math symbol will you use?") 
      ms = io.read()

-- Main function
 function TYPCALC() 

        --If user typed certain math symbols
  if (ms == "division") then

      print ("\n\tWhat number will be divided to?")
          local rn = io.read()

      print ("\n\tWhat will be dividing?")
          local ln = io.read()

          --convert users answers in to strings
          local cln = tonumber(ln)
          local crn = tonumber(rn)

          --do equasion
          io.write (ln / rn)
       end;         

  end ;

    TYPCALC()

There's no built-in fraction type. – Yu Hao Aug 18 '17 at 03:24 — Yu Hao, Aug 18 '17 at 03:24
try use `string.format('%.2f", ln / rn)` – moteus Aug 18 '17 at 06:47 — moteus, Aug 18 '17 at 06:47

Piglet · Answer 1 · 2017-08-18T08:25:06.050

2

Lua does not have a fraction type. You'll have to calculate the numerator and denominator yourself. Then print it.

If you just print or write (number/number2) that expression will be evaluated first, resulting in a decimal number. The function will use a local copy of that number then.

local denominator = 12 -- or some calculated value in your case
local numerator = 1

print(numerator .. "/" .. denominator)

will print 1/12

Another remark:

--convert users answers in to strings
local cln = tonumber(ln)
local crn = tonumber(rn)

If you want to convert a number to a string, you have to use tostring(), not tonumber()

edited Aug 18 '17 at 08:25

answered Aug 18 '17 at 07:04

Piglet

27,501
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I meant to use tonumber(), I just did a typo with the comment. Sorry about that. Also, I am not trying to print fractions, I am trying to print the answer to the division equasion. Sorry again if I didn't clarify well enough. – robotbeta05 Aug 18 '17 at 20:25
@robotbeta05 If you're not trying to print fractions, you should edit your question to make it clear what you're trying to do. – Tanner Swett Aug 21 '17 at 21:32

robotbeta05 · Answer 2 · 2017-08-19T01:57:21.197

-2

I fixed my bug, it turns out that I had to switch the variables places to do the division. Normally you should not have to do this for equations in Lua, but I had to. I ran into this same problem with subtraction, and it fixed that too. Thanks for everyone's help. Here is my change:

io.write (ln / rn)

to

io.write (rn / ln)

edited Aug 19 '17 at 01:57

answered Aug 18 '17 at 20:42

robotbeta05

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it's not clear what you mean. your question was also not very clear. please improve both – Piglet Aug 18 '17 at 20:46
Can you post your solution here? Otherwise this is not a sensible or useful answer. – Thomas W Aug 18 '17 at 20:54

When trying to print division, it converts fractions to decimals

2 Answers2