Simple Tip Calculator with JavaScript Console App Simple console tip calculator app in JavaScript. I would like to get some feedback on improving my code. Thank you beforehand. 

Source code:



//header
const headerMessage = () =&gt; {
  console.log('Tip Calculator')
}

//service quality
const serviceQuality = (billEntered, userOption ) =&gt; {
  const userInput = Number(userOption);
  switch(userInput){
    case 1:
      return (billEntered * 0.3)
      break;
    case 2:
      return(billEntered * 0.2)
      break;
    case 3:
      return(billEntered * 0.1)
      break;
    case 4:
      return(billEntered * 0.05)
      break;
   }
}

const tipCalulcator = () =&gt; {
  headerMessage()
  const enterBill = prompt('Please tell me bill amount: $ ');
  console.log(`Bill amount was $ ${enterBill}`)
  console.log(`How was your service ? Please enter number of the options`)
  const enterOption = prompt(`  1) Outstanding (30%) 
  2) Good (20%)
  3) It was ok (10%)
  4) Terrible (5%)`)

  const result = serviceQuality(enterBill, enterOption);
  console.log(`Tip amount ${result}`)
  const total = Number(enterBill) + result;
  console.log(`Overall paycheck ${total}`)
}

tipCalulcator();
A couple of things to consider:


When dealing with a switch statement, if a case utilizes the return keyword then you do not need to also include a break. When the return is hit, no further code in that function will be reached.
You should handle unexpected inputs; for example, serviceQuality should account for non-numeric inputs, or a number that is not 1-5. Look into try/catch statements and using a default case on your switch.
Because you are not reusing headerMessage, this function is not really required.
Your variable names are fairly unintuitive; consider changing them so that it's more obvious what each thing is such as enterBill -> billAmount and enterOption -> serviceOption. It might be worth using those same names as the serviceQuality arguments too.