Java Training Course/JT03

Main Arguments and String Concatenation

In this session we will pass 2 parameters from the commandline to the program. There we will access, concatenate and output them.

• Create a file DupString.java with the following modified copy of the HelloWorld program of session JT02:

public class DupString {
    public static void main(String[] args) {
        String st0 = args[0]; // the 1st parameter on the commandline
        String st1 = args[1]; // the 2nd ...
        String st2 = st0 + st1;
        st2 = st2 + st2 + st2 + st2;
        System.out.println(st2);
    } // main
} // DupString

• Compile the program in order to be sure that you entered it with the correct syntax.
• Before running the program, tell what you would expect as output from the following command:

java DupString Hello World

• Bonus task: How would you make the output more readable with little effort?

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