If you walk down certain New York City streets at night, where you should not be in the first place, getting mugged is as certain as missing a subway when you are in a hurry to get to work. Some of these neighborhoods are so dangerous that policemen walk in pairs and carry around change to give to muggers if they are held up.
Nothing is guaranteed as a preventative, short of tooling around in a Sherman tank.
But the following are some proven suggestions that might come in handy. Walk around with a paper cup as if you are a homeless person. If he doesn't give you any money, it also helps to look menacingly at him as if you are about to mug him . Then, you might have a big problem. It pays to take a cup with you everywhere you go because you never know.