Some Tips for Passing This Course

CS 509 - Advanced Programming II, Fall 2001

What Happened Last Time

Follow Directions

• Testing is automated.

  If you don't follow directions, your tests will fail and so will you.

• Input

  • Understand std-in, std-out, and command-line arguments.

  • Do not prompt for input.

• Output

  • Follow the output format.

    • Specified:

      Output rectangles one per line with the format x₁ y₁ x x₂ y₂.

    • Implemented:

      THIS SI FINAL DISPLAY OF AN ARRAY 
      { [ 1, 1 ] , [ 3, 3 ] }  Level is  :   0  Position is :   0
      { [ 2, 2 ] , [ 4, 4 ] }  Level is  :   1  Position is :   0
      

  • Debugging output.

    • Send debugging output to std-err (cerr).

    • Turn off debugging output in submissions.

• Do you want to deal with someone who can't follow directions?

Know Your Tools

• Stream I-O.

  • Don't duplicate function.

    • What is going on here?

      void eat_white() {
        while (cin && isspace(cin.peek()))
        cin.ignore();
        }
      
      void f() {
        while(cin && (cin.peek() != EOF)) {
          cin >> s;
          eat_white();
          }
        }
      

  • Understand error and exceptional conditions.

    • Understand and use correctly the end-of-file condition.

• Know your libraries.

  • Unix has a lot of them, and they are here to help you.

  • C++ libraries can get complicated (stream io).

Dynamic Memory is Not Your Friend

• Make sure you need it.

  char *temp = new char[5];
  strcpy(temp,"<FONT");
  char *temp2 = new char[5];
  

• If you do need it, use it correctly.

  bool readInst(List *L, char *&inst, int noInst) {
  
    char * line = new char[80];
  
    inst = new char[80];
    strcpy(inst, "\0");
  
    line = L->getNext();
    if ( line  == NULL ) {
      inst = NULL;
      return false;
      }
  
    // blah blah blah
    }
  

• Programs are tested with limited amounts of memory.

Other Programming Dont's

• Don't use system().

  • It is dangerous, unreliable, and expensive.

  • system() will be broken for testing.

• Don't abuse files.

  • They are unreliable and expensive.

  • Files will be limited for testing.

Test Your Code

• Don't rely on only my tests.

• Work in teams, test each other's code.

• Important for those programming on other systems.

  • Microsoft is more forgiving (read "non-standard") than is Solaris.

  • Disable Microsoft extensions; use strict ANSI-ISO compatibility.

Exhibit Learning Behavior

• Penalties increase as time goes on.

  • The penalty for buffer-overflow errors grows quickly.

• Frowned upon behavior should decrease over time.

• If you read about it, and we talk about it, I should see it in your code.

Other Bits of Advice

• Design before you implement.

  • Know what you're implementing.

• Work in groups of two or three.

  • Design and evaluate the design.

  • Implement alone.

  • Test the implementation.

• Go back and review.

  • You're learning new things - how do they help?

  • You're going to be seeing your mistakes again.

  • It's like music: practice makes perfect.

This page last modified on 6 September 2001.