How do I store an object as variable in another object?

Say I have three object types.

Player, weapon, bullet.

Then I want to have a variable in player for the currently used weapon, and a variable in weapon for the bullet type it uses.

example

player.weapon = lasergun

lasergun.bullet = laserbullet

if left click

player spawn player.weapon.bullet

How should i program these kinds of situations as simple as possible?

It is unclear how many players/weapons do you have on screen in any given time.

But you can use different sprites for different weapons. And one variable for bullet type.

And then check

On click-->

If Weapon1 is on screen -->

if bullet = 1 --> create bullet1 at weapon1.x/weapon1.y

if bullet = 2 --> create bullet2 at weapon1.x/weapon1.y

Create instance by a string name