calculatorLogic.js

/*
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"
*/

//Answer//

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

//OR//

function calculator(a,b,sign){
if (typeof(a)!=='number'||typeof(b)!=='number'){return "unknown value"}
if(sign==='*'){return a*b}else if(sign==='/'){return a/b}else if(sign==='+'){return a+b}else if(sign==='-') {return a-b} else {return 'unknown value'}
}