You should know what you're trying to do before you start programming, yes. (Unless you're exploring the options.) That could just be a task list, if it's a s

You should know what you're trying to do before you start programming, yes. (Unless you're exploring the options.) That could just be a task list, if it's a simple, well-known (to you) problem. If not, then you want more. You want a design, maybe even an architecture. Don't code before thinking and planning. The bigger the program, the more time and detail in the thinking and planning before you start coding.