Guard Returns

Exit a function early when a condition fails.

guard_return.js

const quantity = 2;
function describeOrder(count) {
  if (count <= 0) {
    return "empty";
  }
  return "items=" + count;
}
const summary = describeOrder(quantity);

console.log("quantity=" + quantity);
console.log("summary=" + summary);

guard-return A guard return handles an exceptional or empty case first. The rest of the function can then read like the normal path.