INTRODUCTION TO OBJECTS AND INPUT/OUTPUT - Java Programming: From Problem Analysis to Program Design - page 120

u = 12.5; //Line 2

v = 3.0; //Line 3

System.out.println("Line 4: " + u + " to "
+ "the power of " + v
+ " = " + Math.pow(u, v));

//Line 4

System.out.println("Line 5: Square root of "
+ "42.25 = "
+ Math.sqrt(42.25));

//Line 5

u = Math.pow(8.5, 2.0); //Line 6

System.out.println("Line 7: u = " + u); //Line 7

}

}

Sample Run:

Line 1: 2 to the power of 6 = 64.0
Line 4: 12.5 to the power of 3.0 = 1953.125
Line 5: Square root of 42.25 = 6.5
Line 7: u = 72.25

The preceding program works as follows. The statement in Line 1 uses the function pow
to determine and output 2 6 . The statement in Line 2 sets u to 12.5 , and the statement in
Line 3 sets v to 3.0 . The statement in Line 4 determines and outputs u v . The statement
in Line 5 uses the method sqrt , of the class Math , to determine and output the square
root of 42.25 . The statement in Line 6 determines and assigns 8.5 2 to u . The statement
in Line 7 outputs the value of u .

Dot Between Class (Object) Name and Class Member:
A Precaution
In Chapter 2, you learned how to use the method nextInt of the class Scanner to
input the next token, which can be expressed as an integer. In the preceding section, you
learned how to use the method pow of the class Math .
Consider the following statement:

x = console.nextInt();
where x is a variable of type int . Notice the dot between console and nextInt ; the name
of the object console and the name of the method nextInt are separated by the dot.
In Java, the dot ( . ) is an operator called the member access operator.
Omitting the dot between console and nextInt results in a syntax error. In the
statement:

x = consolenextInt();