Methods and Formatted Output - Learning Java Through Games - page 67

for ( int i=0; i < n ; i ++) {
System. out . print (c) ;

}

}

Now we can rewrite our code for printing a diamond as follows.

import java . util . ∗ ;

public class Diamond {
public static void printStrings(String s , int n) {
for ( int i=0; i < n ; i ++) {
System. out . print ( s ) ;

}
} public static void main(String [] args)

{
Scanner keyboard = new Scanner(System. in) ;
System. out . print ( "Enter size of diamond: " );
int size = keyboard.nextInt() ;
for ( int numStars =1, numSpaces = size − 1; numSpaces > =0 ; numSpaces
− =2, numStars+=2) {
printStrings( "" ,numSpaces) ;
printStrings( "* " ,numStars) ;
System. out . println () ;
for ( int numStars=size − 2, numSpaces = 2; numStars > =0 ; numSpaces
+=2, numStars − =2 ) {
printStrings( "" ,numSpaces) ;
printStrings( "* " ,numStars) ;
System. out . println () ;

}

}

}

The code is not necessarily shorter, but it is easier to understand. When we want to
print a number of characters, we simply call our friend printStrings . He will print as many
stringsaswewantforfree!Next,notethatweprintalineinthesamewaywhenweprint
the top and the bottom of the diamond. Therefore, we can create a method that prints a
line.
public static void printLine( int numSpaces , int numStars) {

printStrings( "" ,numSpaces) ;
printStrings( "* " ,numStars) ;
System. out . println () ;

}

Now, our main method will call the printLine method when we want to print a line. The
number of spaces and stars in the line are specified as parameters. The printLine method
in turn calls the printStrings method twice to print the spaces and stars, respectively.
The new version of the code is shown below.

import java . util . ∗ ;

public class Diamond {
public static void printStrings(String s , int n) {

for ( int i=0;i < n ; i ++) {

System. out . print ( s ) ;