1+1 = 10, 1+2 = 3

Question

Write a function or program than can do simple arithmetic (addition, subtraction, multiplication and division) in both base 10 and base 2.

The function will take a mathematical expression as input, and output the correct result in the correct base. The input will be n numbers separated by one or several operators (+ - * /).

If all input values contain only 0 and 1, all values are considered to be binary. If at least one digit is 2-9, all values are considered to be base 10.

Rules:

• You can assume there will only be one operator between numbers (10*-1 will not appear)
• You can assume there will be no parentheses.
• Normal operator precedence (try the expression in the google calculator if you're in doubt).
• You can not assume there will only be integers
• There will be no leading zeros in input or output
• You can assume only valid input will be given
• You can assume all input values are positive (but the minus operator may make negative output possible, 1-2=-1 and 10-100=-10)
• REPL is not accepted
• You may choose to take the input as separate arguments, or as a single argument, but the input has to be in the correct order.
  • I.e. you may represent 1-2 with the input arguments 1, -, 2, but not 1, 2, -.
• You must accept the symbols + - * / in the input, not plus, minus etc.
• You must support floating point values (or up to the maximum limit of your language, however supporting only integers is not accepted).
• eval is accepted

Examples:

1+1
10

1010+10-1
1011

102+10-1
111

1+2+3
6

10*10*10
1000

11*11*11
11011

10*11*12+1
1321

10.1*10.1
110.01

20.2*20.2
408.04

10/5
2

110/10
11

Also accepted (optional line or comma-separated input):
10
+
10
-
1
11    <-- This is the output

This is code golf, so the shortest code in bytes will win.

Answer 1

JavaScript ES6, 87 97¹ 100² 106³ 102 101 98 100⁴ 93 88 86 bytes

e=>eval(e.match`[2-9]`?e:`(${e.replace(/[\d.]+/g,"('0b'+$&e14)/16384")}).toString(2)`)

Demo + explanation:

function c(e){
    return eval(                        
      e.match`[2-9]`?                  //check if there are numbers 2 to 9
        e:                             //if there're, just compute the result
        "("+                           
         e.replace(                    //otherwise replace...
           /[\d.]+/g,                  //any number...
           "(('0b'+$&e14)/16384)"    //...with itself converted to base 10
         )
        +").toString(2)"               //compute the result and convert it to binary
    )
}

document.write(
   c("1.1*1.1")+"<br>"+
   c("1010+10-1")+"<br>"+
   c("102+10-1")+"<br>"+
   c("1+2+3")+"<br>"+
   c("10*10*10")+"<br>"+
   c("11*11*11")+"<br>"+
   c("10*11*12+1")+"<br>"+
   c("10.1*10.1")+"<br>"+
   c("20.2*20.2")+"<br>"+
   c("10/5")+"<br>"+
   c(`10
      +
      10
      -
      1`)
)

---

^{1 - forgot about floats
2 - again floats problem: parseInt floors binary so I have to multiply by 1e14 and then divide by 16384
3 - hope that's achieved the given task, now start to golf :D
4 - there was a bug with dividing}

Answer 2

Japt, 77 72 62 60 62^* 60 59 51 bytes

OvUf"[2-9]" ?U:"({Ur"[\\d.]+""º$&e14+P n2 /2pE¹"})¤

Explanation (more or less the same as for the JS answer):

Ov                       //eval...
  Uf"[2-9]"              //if input contains the digits 2 to 9
    U:                   //then it's base 10, just compute
    Ur"[\\d.]+"          //otherwise replace all the numbers
    "º$&e14+P n2 /2pE¹"  //with their base 10 equivalents
                         //I.e., take every number, multiple by 10^14, convert to
                         //base 10 and divide by 2^14
                         // º and ¹ are multiple brackets
    ¤                    //means "s2", i.e. convert the result to binary
                 

Try it online!

---

^{* didn't divide properly}

Answer 3

Jolf, 31 bytes, noncompeting

I added a decent amount of functions inspired by this challenge, and, as thus, it is considered noncompeting. I'm happy because I finally implemented unary functions (like (H,S,n)=>val in ES6, but are supported in ES5!)

? hi"[2-9]"~eiB~epT mpvid|m'H2H
? hi"[2-9]"                     if the input contains any of 2..9
           ~ei                   evaluate i (implicitly print)
                                else
                   _mpvid        map the input split into number groups
                          m'H2    to H as a binary float
                         |    H   (or keep H, if that doesn't work)
                 pT              join by spaces
               ~e                evaluate
              B                  convert to binary (implicitly print)

Test suite, Try your own input, or manually set the input.

Answer 4

Bash, 60 bytes

[ -z `tr -dc 2-9<<<$1` ]&&s='obase=2;ibase=2;';bc -l<<<$s$1

Example Run:

$ ./bin_dec_add.sh 1+1
10
$ ./bin_dec_add.sh 1+2
3

Answer 5

𝔼𝕊𝕄𝕚𝕟 2, 46 chars / 72 bytes

ë(ïđ/[2-9]⎞?ï:`(⦃ïē/[\d.]+⌿,↪(Յ+$*ḊⁿḎ)/Ẁ²)})ⓑ`

Try it here (Firefox only).

Explanation

ë(ïđ/[2-9]⎞?ï:`(⦃ïē/[\d.]+⌿,↪(Յ+$*ḊⁿḎ)/Ẁ²)})ⓑ` // implicit: ï=input, Ḋ=10, Ḏ=14, Ẁ=128
ë(                                              // eval
  ïđ/[2-9]⎞?                                    // does ï have 2-9?
            ï                                   // if so, eval input
             :                                  // else, eval:
              `(⦃ïē/[\d.]+⌿,                    // replace the binary numbers
                                                // with their base 10 equivalents:
                            ↪(Յ+                // translates to `0b`
                                $*ḊⁿḎ           // matched number * 10^14
                                     )/Ẁ²       // divided by 128^2
                                         )})ⓑ` // converted to binary
                                                // implicit output

Answer 6

PowerShell, 107 bytes

param($e)iex(("{0}String($($e-replace'(\d+)','{0}Int32("$1",2)'),2)"-f'[Convert]::To'),$e)[$e-match'[2-9]']

Ungolfed

param($e) # Accept single argument
Invoke-Expression # Eval
  ( # Expression, resulting in an array of 2 elements
    (
      "{0}String( # Binary
        $( # Inline subexpression
          $e -replace'(\d+)', '{0}Int32("$1",2)'
          # "1010+10-1" becomes "{0}Int32("1010",2)+{0}Int32("10",2)-{0}Int32("1",2)"
        )
      ,2)"
      -f '[Convert]::To'
      # "{0}Int32("1010",2)+{0}Int32("10",2)-{0}Int32("1",2)" becomes
        "[Convert]::ToString([Convert]::ToInt32("1010",2)+[Convert]::ToInt32("10",2)-[Convert]::ToInt32("1",2),2)"
    ),
      $e # Plain
    )
    [$e-match'[2-9]'] # Return 1st element of array if regex matches, else 0

Example

PS > .\Calc.ps1 1010+10-1
1011

PS > .\Calc.ps1 20.2*20.2
408,04