13. EchoSquare.java

Answer:
 4              OK
 
    45          OK 
    
 456            OK 
 
 923X           BAD
 
     23   876   OK: the first group ends after the "3"
The last line is OK. If there is a second call to nextInt() it will pick up the "876" .

EchoSquare.java

Here is the program shown in the previous picture. It computes the square of an integer entered (as characters) by the user.
import java.util.Scanner;

public class EchoSquare
{
  public static void main (String[] args)
  { 
    Scanner scan = new Scanner( System.in );
    int num, square;      // declare two int variables 

    System.out.println("Enter an integer:");
    num = scan.nextInt();
    square = num * num ;  // compute the square 

    System.out.println("The square of " + num + " is " + square);
  }
}

Here is a picture of it running:

EchoSquarePicture

Please run this program and play with it. Beginning programmers are often confused about "character data" and "numeric data" and conversions between the two. Take the opportunity to make sure you know what is going on to avoid future confusion.

Question 13:
Do you think that the following input would work with this program?
twelve hundred