Its more of a what you would have done as the scenario happened this afternoon.
I was on a work break and had my phone (i dont have applepay or googlepay on my phone) and some cash with me, and was about to go into a shop when I was stopped by a homeless man. He said "excuse me excuse me," and physically blocked my path by moving side to side so i wouldnt walk past, and said he was homeless and needed food and £10 towards a hostel for the night. I pointed to tesco metro, and said what do you want, I'll buy you something. And then he said he didn't want food, he wanted £20 for the hostel. And then pointed to the cash point, and said there's a cash point here.
I told him I'm buying something in the shop, I will give you some change on the way out. I bought what I wanted and I gave him £5 on the way out. He immediately asked had I got any more, and said he needed £20. And then said can I ask you a question, and I said no, and walked away.
I felt bad about it but I also felt pretty intimidated. (He was probably a foot taller than me) I told DH later, and he said he wouldn't have given him anything.