eggheadio-projects/getting-started-with-redux: null

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Plunker</title>
</head>
<body>

</body>
</html>

// Pure functions
function square(x) {
  return x * x;
}
function squareAll(items) {
  return items.map(square);
}

// Impure functions
function square(x) {
  updateXInDatabase(x);
  return x * x;
}
function squareAll(items) {
  for (let i = 0; i < items.length; i++) {
    items[i] = square(items[i]);
  }
}