Hi
I am reading a book about Java . It says that "There are three ways to
call a method

1 - Using a method name by itself to call another method of the same
classsuch as maximum( number1, number2, number3 ) in line 21
2 - ........
3 - ........

I can not understand number 1

// Fig. 6.3: MaximumFinder.java
// Programmer-declared method maximum.
import java.util.Scanner;

public class MaximumFinder
{
  // obtain three floating-point values and determine maximum value
  public void determineMaximum()
  {
     // create Scanner for input from command window
     Scanner input = new Scanner( System.in );

     // prompt for and input three floating-point values
     System.out.print(
        "Enter three floating-point values separated by spaces: " );
     double number1 = input.nextDouble(); // read first double
     double number2 = input.nextDouble(); // read second double
     double number3 = input.nextDouble(); // read third double

     // determine the maximum value
     double result = maximum( number1, number2, number3 );

     // display maximum value
     System.out.println( "Maximum is: " + result );
  } // end method determineMaximum

  // returns the maximum of its three double parameters
  public double maximum( double x, double y, double z )
  {
     double maximumValue = x; // assume x is the largest to start

     // determine whether y is greater than maximumValue
     if ( y > maximumValue )
        maximumValue = y;

     // determine whether z is greater than maximumValue
     if ( z > maximumValue )
        maximumValue = z;

     return maximumValue;
  } // end method maximum
} // end class MaximumFinder