Homework 2, Feedback.

Notes

• Make sure you take the attendance quiz each week.
• If you turned in a pdf file, you lost a point. You were told to create a word document. You were told to submit your word document.
• You Makefile should be named Makefile, not Makefile.h or Makefile.txt.
• If something doesn't work, don't just ignore it. ASK.
• What is the difference between "compile" and "execute"?

Answers

1. What will happen when hw2a.cpp is compiled?
   • This all legal code. There will be no warnings or errors, even though there are major "mistakes" in the code.
2. What happened when hw2a.cpp was compiled with g++ -o hw2a hw2a.cpp
   • It compile just fine.
3. Provide an example of a statement that produces a syntax error.
   • There are many reasonable answers to this question.
4. What are the compiler warnings produced when using the command line flags to g++ and what do they mean?

   hw2a.cpp: In function 'int main()':
   hw2a.cpp:11:13: warning: declaration of 'i' shadows a previous local [-Wshadow]
      11 |         int i = 4;
         |             ^
   hw2a.cpp:6:9: note: shadowed declaration is here
       6 |     int i;
         |         ^
   hw2a.cpp:8:13: warning: 'i' is used uninitialized in this function [-Wuninitialized]
       8 |     cout << i << endl;
         |             ^ 

   • In line 11, there is a second declaration of i. This is legal because it is inside a new scope, the scope of the while loop. It is, however not a good idea.
   • Line 13 produces a warning that i, (the one defined on line 6) was not initialized. This is bad as well.
     • I think the compiler is confused here however. The i in question is the i that was declared inside the loop.
5. Why does how2a.cpp execute an infinite loop and how is this related to the shadow declaration warning?
   • The LCV i and the i printed out and incremented are two different i's.
   • To be more sure of your answer change i+= i; to i = i + 10;
6. What caused the infinite loop in hw2b.cpp
   • The while statement is ill-formed. The body should be in a code block. The way it is written the increment is outside of the loop.
7. What does the command line flag -Wmisleading-indentation cause the compiler to report?
   • Exactly the problem that caused the error in execution.
8. How does make simplify the compiling process with respect to compiler flags?
   • This allows the programmer to use the compiler flags WITHOUT having to remember to type them each time.