I began this problem by creating my class and main, and declaring my variables. I figured that I needed 2 variables of class double for storing user input and the output from the calculation, and 1 variable type string for the unit the user wanted to convert (C/F). I realized shortly afterwards that i would need another variable of type string for the user to input whether they wanted to continue convering or not (Y/N). 

I knew that I would need a while loop, so the user could repeat the program several times if they wanted. I began with a while the condition.equals "Y" and prompted the user to enter a temperature with an output, and an input using scanner. Then I asked for the units the same way and began with a if statement for each circumstance, celcius or fahrenheit. If the user entered a C, i made a formula for the output using the formula given, and vice versa for fahrenheit. I then printed out the conversion and prompted the user to enter whether they wanted to continue (Y/N) using scanner. I ctlr c + v this if statement and replaced the formula with the one for fahrenheit given. 

After this I compiled and debugged my program a bit before giving it a try. Immediately I realized I had a few things to tweak, specifically that the program crashed if the person didnt enter exactly a capital F or C, same with the Y or N prompt. Also their was a problem if a person entered a string instead of a number in the temperature input. After some research I learned about the equalsIgnoreCase which I could use in my while and if statements so that it didn't matter whether the letter entered was capital or lowercase. I also wanted the user to be prompted to enter a f or c if they entered something else, so I added an else statement at the end of my while loop that would be triggered if the input was something different than a C or F. 

The only issue I had remaining was the problem where if a person entered something other than a number for a temperature the program would crash. I played around with trying to figure out exceptions and try...catch statements but couldn't get anything to work. I also tried an if statement but it made my program not work at all so I took it out and left the bug. Maybe I will learn how to change this further on in the course.

I now have a working try...catch statement, had quite a bit of problems getting the user to go back to the prompt afterwards then learned about the continue; statement in java which brings the user back to the start of a loop. Now I have a method for catching invalid data for both input types.