4.2.5

The

boolean

 Type and

boolean

 Values

TYPES, VALUES, AND VARIABLES

//

Another example of inexact results and rounding:

System.out.print("inexact results with double:");

for (int i = 0; i < 100; i++) {

double z = 1.0 / i;

if (z * i != 1.0)

System.out.print(" " + i);

}

System.out.println();

//

An example of cast to integer rounding:

System.out.print("cast to int rounds toward 0: ");

d = 12345.6;

System.out.println((int)d + " " + (int)( d));

}

}

produces the output:

overflow produces infinity: 1.0e+308*10==Infinity

gradual underflow: 3.141592653589793E 305

3.1415926535898E 310 3.141592653E 315 3.142E 320 0.0

0.0/0.0 is Not a Number: NaN

inexact results with float: 0 41 47 55 61 82 83 94 97

inexact results with double: 0 49 98

cast to int rounds toward 0: 12345  12345

This example demonstrates, among other things, that gradual underflow can

result in a gradual loss of precision.

The inexact results when

i

 is

0

 involve division by zero, so that

z

 becomes

positive infinity, and

z * 0

 is NaN, which is not equal to

1.0

.

4.2.5   The

boolean

 Type and

boolean

 Values

The

boolean

 type represents a logical quantity with two possible values, indi 

cated by the literals

true

 and

false

 ( 3.10.3). The boolean operators are:

The relational operators

==

 and

!=

 ( 15.20.2)

The logical complement operator

!

 ( 15.14.6)

The logical operators

&

,

^

, and

|

 ( 15.21.2)

The conditional and and conditional or operators

&&

 ( 15.22) and

||

 ( 15.23)

The conditional operator

? :

 ( 15.24)

The string concatenation operator

+

 ( 15.17.1), which, when given a

String

operand and a boolean operand, will convert the boolean operand to a

String

(either

"true"

 or

"false"

), and then produce a newly created

String

 that is

the concatenation of the two strings

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