Question

I have a task that requires me to print out the following quantities:

I need to write a java program that can calculate:
1. the number of integers read in
2. the average value—which need not be an integer!

My final output should look like:

$ javac SimpleCalc 
$ java SimpleCalc 3 4 6 8 1 
5
8
4.4 
7

I know i need to use a scanner class to read then as the user inputs then, i dont know how to make it display a count. I think that i can work this out, i can compute the average by adding up the numbers and divide the toal by the number of integers entered.

However its my first time writing a program, and this is doing my head in. Any help would be appreciated, ill even accept pseudocode if it helps me work out how to approach this.

Answer 1

Here you are supposed to use the arguments of the main function:

public class PrintArgs {
    public static void main (String[] args) {
        for (int i = 0; i<args.length; ++i) {
          System.out.println("Args " + (i + 1) + " is " + args[i]);
        }
    }
}

Save this class in a file called PrintArgs.java and compile it using javac:

$ javac PrintArgs.java

Run the generated class file using java:

$ java PrintArgs hello world
Args 1 is hello
Args 2 is world

$ java PrintArgs 3 4 6 8 1 
Args 1 is 3
Args 2 is 4
Args 3 is 6
Args 4 is 8
Args 5 is 1

Now you know how to read input from the user. To convert a String to int, use the parseInt method of the Integer class:

int i = Integer.parseInt("980");
System.out.println(100 + i); // => 1080

Now you know how to write your calculator program!