Crear Una Calculadora

function add(a, b) {
  return a + b;
}

function subtract(a, b) {
  return a - b;
}

function multiply(a, b) {
  return a * b;
}

function divide(a, b) {
  return a / b;
}

var calculate = function(num1, operator, num2) {
  if (operator === '+') {
    return add(num1, num2);
  } else if (operator === '-') {
    return subtract(num1, num2);
  } else if (operator === '*') {
    return multiply(num1, num2);
  } else if (operator === '/') {
    return divide(num1, num2);
  }
};

calculate(1, '+', 2);
calculate(4, '-', 2);
calculate(2, '*', 0);
calculate(12, '/', 0);