Avoid Mental Mapping

Explicit is better than implicit.

Bad:

const locations = ["Austin", "New York", "San Francisco"];
locations.forEach(l => {
  doStuff();
  doSomeOtherStuff();
  // ...
  // ...
  // ...
  // Wait, what is `l` for again?
  dispatch(l);
});

Good:

const locations = ["Austin", "New York", "San Francisco"];
locations.forEach(location => {
  doStuff();
  doSomeOtherStuff();
  // ...
  // ...
  // ...
  dispatch(location);
});