Javascript Calculator

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;
}

function invokeMe(string, array) {
  if (typeof window[string] === "function") {
    return window[string].apply(null, array);
  }
}

function calc1(action, a, b) {
  if (action == "add") {
    return add(a, b);
  } else if (action == "subtract") {
    return subtract(a, b);
  } else if (action == "multiply") {
    return multiply(a, b);
  } else if (action == "divide") {
    return divide(a, b);
  } else {
    return "Something went wrong";
  }
}

function calc2(string, array) {
  var actions = ["add", "subtract", "multiply", "divide"];

  if (actions.includes(string)) {
    return invokeMe(string, array);
  } else {
    console.log("not a valid action");
    return null;
  }
}