You are required to create a simple calculator that returns the result of addition, subtraction, multiplication or division of two numbers.

Your function will accept three arguments:
The first and second argument should be numbers.
The third argument should represent a sign indicating the operation to perform on these two numbers.

if the variables are not numbers or the sign does not belong to the list above a message “unknown value” must be returned.

Example:

calculator(1,2,"+"); //=> result will be 3
calculator(1,2,"&"); //=> result will be "unknown value"
calculator(1,"k","*"); //=> result will be "unknown value"

Solution

function calculator(a,b,sign){
 try {
    return eval(`${a} ${sign} ${b}`)
  } catch (e) {
    return 'unknown value'
  }

}