Although a lot of martial art weapons are dated since the invention of gun powder, training in these weapons can still be quite useful to enhance your skills and overall understanding of combat. A weapon is a force multiplier. It lets you do more damage to your opponent, with less effort and exertion, in a shorter period of time, while exposing yourself to less danger of injury. Having trained with weapons can help you in a self-defence situation. This is particularly true if you have trained in weapons that can be simulated by everyday objects, and thus close at hand.
Don't have a long staff? A broom will do.
No sword? An umbrella.
No short sticks? Your mini-umbrella or a timber baton.
No rope handy? Use your belt or a towel to strike, choke or tie up your opponent.
No ninja stars? Throw your keys, coins or dirt into an opponents eyes.
No shield? Use a cooking pot or even cover your arm with clothing to protect from sharp weapon attacks.