You have gone to a friends house and want to know his wifi password without asking him? If your friend has a windows pc and you have access to it for just 10 seconds then you are lucky.
Wifi password showing tricks with windows cmd
copy below code and paste it to a notepad and save it as a anything.cmd file
@echo off
color 0a
title Intel.dll
netsh wlan show profile "YOUR_WIFI_SSID" key=clear >Pass.txt
Then run it by double clicking the .cmd file.
You will find a file in called Pass.txt Open the file and there you will find the wifi password.