CS 313e - Command Line Arguments

Feedback questions:
0. How well do you understand the sorting algorithms?
1. Write down the algorithm for selection sort. Assume you want to sort the elements of an array A of N elements into ascending order.


Command Line Arguments

Command-line arguments = strings that follow the name of the application program on the command line when the program is executed.

Ex: Suppose you have a program called FileCopy that copies one file to another. To compile this program, you type
javac FileCopy.java

To run this program, you type:
java FileCopy oldFile.txt newFile.txt
                              ^              ^
                          args[0]        args[1]

Note: The command line arguments are Strings - they are passed to the main method of your program in the String array called args.
Recall the main method header: public static void main(String[] args)

Ex: The PrintWriter object for your FileCopy program

PrintWriter writer = new PrintWriter(new BufferedWriter(new FileWriter(args[1])));

Exercise: Write the FileCopy program.
    Hint: Check the number of command line arguments, and print an error message if it's incorrect.

Example: Write a program that takes a word on the command line and prints it to the screen.