Bouncer pattern explaining early return

bouncerPattern.js

function calculateSomeFormula(param1, param2) {

  validateParams(param1, param2);

  return (param1 * 2) * (param2 * 3);
}

// although return value is not used in our example but this method can also return value which can be used by the caller 
function validateParams(param1, param2) {
  if (!param1) {
    throw new Error('Param1 is not defined');
  }

  if (isNaN(param1)) {
    throw new Error('Param1 is not a number');
  }

  if (!param2) {
    throw new Error('Param2 is not defined');
  }

  if (isNaN(param2)) {
    throw new Error('Param2 is not a number');
  }

  return true;
}