Refactoring

Questions 1 to 5 of 6

1. 1. Put the four rules of the refactoring method in the order you follow them.

   Use the arrows to put the steps in order.

   1. 1.Compile with -Wall, run the program, and save its new output↑↓
   2. 2.Compare the new output with the saved output, and undo the change if they differ↑↓
   3. 3.Make one small change, such as moving one group of lines into a function↑↓
   4. 4.Save the output of the working program to a file before any change↑↓
2. 2. Put the three cuts of the receipt refactor in the order the lesson makes them.

   Use the arrows to put the steps in order.

   1. 1.Step 3: pull out print_items and print_totals↑↓
   2. 2.Step 1: pull out compute_subtotal, the loop that adds up the items↑↓
   3. 3.Step 2: pull out compute_discount and compute_tax↑↓
3. 3. In step 2, the line int tax = compute_tax(subtotal); prints Tax: 89 instead of Tax: 80. Why?

   The tax function rounds every result upTax is taken on 1115 instead of 1004, and 1115 * 8 / 100 is 89print_totals prints the wrong variableInteger division adds one to every result
4. 4. Why is the saved output file made from the original program, before any change, and not after each step?

   So the file can be shared with the teamBecause diff can only read files made before the program is compiledSo the program runs faster when it reads the fileSo each step is compared with the behaviour before the refactor, and a wrong change cannot become the new reference
5. 5. What is wrong with this function? ``cpp int compute_tax(int taxable) { int tax = taxable * 8 / 100; } ``

   It has a syntax error, so the file will not compileThe tax formula is wrong, and the compiler reports it as a type mismatchIt never returns tax, so a caller gets an unpredictable value, and the compiler only warns about itIt must be declared void, because it does not return a value