Looking at the printf method
A printf format reference page (cheat sheet)
// This class shows how to initialize an array
// How to use the printf output formatting method
public class InitPrintfArray
{
public static void main( String[] args )
{
// initializing the array when it is created
int[] arrayA = { 87,56,78,99,102 };
System.out.printf( "%s%7s\n", "Index", "Value" ); // column headings
// output each array element's value
for ( int i = 0; i < arrayA.length; i++ )
System.out.printf( "%5d%5d\n", i, arrayA[ i ] );
} // end main
} // end class InitPrintfArray
A "simplified" version of a bar chart by using the elements of an array as counters
// Bar graph printing program.
public class BarGraph
{
public static void main( String[] args )
{
int[] arrayA = { 0, 0, 0, 0, 0, 0, 1, 2, 4, 2, 1 };
System.out.println( "Grade distribution:" );
// for each array element, output a bar of the chart
for ( int i = 0; i < arrayA.length; i++ )
{
// output bar label ( "00-09: ", ..., "90-99: ", "100: " )
if ( i == 10 )
System.out.printf( "%5d: ", 100 );
else
System.out.printf( "%02d-%02d: ",
i * 10, i * 10 + 9 );
// print bar of asterisks
for ( int stars = 0; stars < arrayA[ i ]; stars++ )
System.out.print( "*" );
System.out.println(); // start a new line of output
} // end outer for
} // end main
} // end class BarGraph
Grade distribution:
00-09:
10-19:
20-29:
30-39:
40-49:
50-59:
60-69: *
70-79: **
80-89: ****
90-99: **
100: *
Claswork/Homework:
Tracing 101: Trace the i, arrayA[i], and the output as the inner and outer loops traverse arrayA.
