What is the pseudo-array arguments? How does it differ from a regular array?

The pseudo-array arguments is an object available inside functions in JavaScript that contains all the passed arguments. It resembles an array because it has numeric indices and a length property, but it is not a full-fledged array: it lacks array methods such as forEach, map, filter, etc.

Differences from a regular array:

• arguments does not inherit array methods.
• It does not support array methods directly.
• It can be converted into a real array, for example, using Array.from or the spread operator.

Example:

function example() {
  console.log(arguments.length); // number of arguments
  // arguments.forEach(...) will cause an error
  const argsArray = Array.from(arguments);
  argsArray.forEach(arg => console.log(arg));
}
example(1, 2, 3);