CS5JA Guest Lecture, Wednesday 03/05/2008
Phill Conrad, substituting for Diana Franklin

Today's topics: reinforce command line args, and reading from a file

• Writing a program to count all the words in a text file
• Plan: try something easier first
  • first write a program to count all the lines in a file
  • then modify it to count all the words in a file
• Input: name of a file
  • we'll take it from the command line
• Output:
  • number of lines (or words) in the file

We will proceed in a number of phases, showing how the program evolves at each step.

Along the way, we might review a bit about "scope" too: where a variable is defined.

• Remember: braces { } are like Vegas:
  • What happens in Vegas, stays in Vegas
  • For the most part: what happens inside a set of braces, stays inside that set of braces
  • This is not a hard and fast rule, but a general guideline...

Program Code:

Note that this code was put online before class, so it may not reflect any changes made during the lecture.

Finished Products:

• CmdLineArgs
• Counting Lines
• Counting Words

In-between versions (some of which have syntax errors, or logic errors)

• Counting Lines
• Counting Words