print() and println()

The print(String s) method of PrintStream sends the characters referenced by s to the output stream. No line separator characters are sent after them. The println(String s) method sends the same characters followed by line separator characters.

Both methods can be used to output numerical results as characters the same way we have been doing with System.out.println(). Here is a program that does this:

import java.io.*;

class PrintSquare
{

  public static void main ( String[] args )  throws IOException
  {
    File file = new File( "mySquare.txt" );
    PrintStream  print = new PrintStream( file );

    double x = 1.7320508;

    print.println( "The square of " + x + " is " + x*x );  

    print.close();
  }
}

The following

"The square of " + x + " is " + x*x

creates one long string by converting x and x*x to character form and then appending those characters to the string literals. It is this final long string that is the argument to println(). Here is a run of the program:

C:\> javac PrintSquare.java
C:\> java PrintSquare
C:\> type mySquare.txt
The square of 1.7320508 is 2.9999999737806395

The program does not send any output to the command window. To see the output of the program you have to look at the file it creates.