tuple

A tuple looks like a list, but once it's created, it can't be changed — no adding, removing, or replacing items.

JS doesn't have a true built-in equivalent — the closest is Object.freeze() on an array:

const point = Object.freeze([4, 5]);

Python has a dedicated syntax for this — parentheses instead of square brackets:

point = (4, 5)

Indexing and slicing work exactly the same as with a list:

point[0]     # 4
point[-1]    # 5

But trying to change it fails:

point[0] = 10
# ❌ TypeError: 'tuple' object does not support item assignment

Why use a tuple?

Use a tuple when a value shouldn't change after it's created — for example, coordinates, an RGB color, or a fixed pair of values returned from a function. It signals to anyone reading the code: "this is a fixed collection, not something to mutate."

def get_coordinates():
    return (12.9716, 77.5946)

lat, lng = get_coordinates()

That last line — unpacking a tuple straight into two variables — is something JS can also do, via array destructuring:

const [lat, lng] = getCoordinates();