Javac problems file not found,source etc command prompt

maybe you are in wrong directory or class name is not correct. or javac is not installed.

maybe you are in wrong directory or class name is not correct. or javac is not installed.

$ javac -version if it prints your version of jdk then it is installed otherwise you need to put the path of your jdk in environment variables.

yeah i already installed javac

but how to know if javac installed

please i need help please