public
final
class
Boolean
extends Object
implements
Serializable,
Comparable<Boolean>
| java.lang.Object | |
| ↳ | java.lang.Boolean |
The Boolean class wraps a value of the primitive type
boolean in an object. An object of type
Boolean contains a single field whose type is
boolean.
In addition, this class provides many methods for
converting a boolean to a String and a
String to a boolean, as well as other
constants and methods useful when dealing with a
boolean.
Fields | |
|---|---|
public
static
final
Boolean |
FALSE
The |
public
static
final
Boolean |
TRUE
The |
public
static
final
Class<Boolean> |
TYPE
The Class object representing the primitive type boolean. |
Public constructors | |
|---|---|
Boolean(boolean value)
Allocates a |
|
Boolean(String s)
Allocates a |
|
Public methods | |
|---|---|
boolean
|
booleanValue()
Returns the value of this |
static
int
|
compare(boolean x, boolean y)
Compares two |
int
|
compareTo(Boolean b)
Compares this |
boolean
|
equals(Object obj)
Returns |
static
boolean
|
getBoolean(String name)
Returns |
int
|
hashCode()
Returns a hash code for this |
static
int
|
hashCode(boolean value)
Returns a hash code for a |
static
boolean
|
logicalAnd(boolean a, boolean b)
Returns the result of applying the logical AND operator to the
specified |
static
boolean
|
logicalOr(boolean a, boolean b)
Returns the result of applying the logical OR operator to the
specified |
static
boolean
|
logicalXor(boolean a, boolean b)
Returns the result of applying the logical XOR operator to the
specified |
static
boolean
|
parseBoolean(String s)
Parses the string argument as a boolean. |
String
|
toString()
Returns a |
static
String
|
toString(boolean b)
Returns a |
static
Boolean
|
valueOf(String s)
Returns a |
static
Boolean
|
valueOf(boolean b)
Returns a |
Inherited methods | |
|---|---|
 From
class
java.lang.Object
| |
From
interface
java.lang.Comparable
| |
Boolean FALSE
The Boolean object corresponding to the primitive
value false.
Boolean TRUE
The Boolean object corresponding to the primitive
value true.
Class<Boolean> TYPE
The Class object representing the primitive type boolean.
Boolean (boolean value)
Allocates a Boolean object representing the
value argument.
Note: It is rarely appropriate to use this constructor.
Unless a new instance is required, the static factory
valueOf(boolean) is generally a better choice. It is
likely to yield significantly better space and time performance.
| Parameters | |
|---|---|
value |
boolean:
the value of the Boolean.
|
Boolean (String s)
Allocates a Boolean object representing the value
true if the string argument is not null
and is equal, ignoring case, to the string "true".
Otherwise, allocate a Boolean object representing the
value false. Examples:
new Boolean("True") produces a Boolean object
that represents true.
new Boolean("yes") produces a Boolean object
that represents false.
| Parameters | |
|---|---|
s |
String:
the string to be converted to a Boolean.
|
boolean booleanValue ()
Returns the value of this Boolean object as a boolean
primitive.
| Returns | |
|---|---|
boolean |
the primitive boolean value of this object.
|
Developers
int compare (boolean x,
boolean y)
Compares two boolean values.
The value returned is identical to what would be returned by:
Boolean.valueOf(x).compareTo(Boolean.valueOf(y))
| Parameters | |
|---|---|
x |
boolean:
the first boolean to compare |
y |
boolean:
the second boolean to compare |
| Returns | |
|---|---|
int |
the value 0 if x == y;
a value less than 0 if !x && y; and
a value greater than 0 if x && !y |
int compareTo (Boolean b)
Compares this Boolean instance with another.
| Parameters | |
|---|---|
b |
Boolean:
the Boolean instance to be compared |
| Returns | |
|---|---|
int |
zero if this object represents the same boolean value as the argument; a positive value if this object represents true and the argument represents false; and a negative value if this object represents false and the argument represents true |
| Throws | |
|---|---|
NullPointerException |
if the argument is null |
See also:
boolean equals (Object obj)
Returns true if and only if the argument is not
null and is a Boolean object that
represents the same boolean value as this object.
| Parameters | |
|---|---|
obj |
Object:
the object to compare with. |
| Returns | |
|---|---|
boolean |
true if the Boolean objects represent the
same value; false otherwise.
|
boolean getBoolean (String name)
Returns true if and only if the system property
named by the argument exists and is equal to the string
"true". (Beginning with version 1.0.2 of the
JavaTM platform, the test of
this string is case insensitive.) A system property is accessible
through getProperty, a method defined by the
System class.
If there is no property with the specified name, or if the specified
name is empty or null, then false is returned.
| Parameters | |
|---|---|
name |
String:
the system property name. |
| Returns | |
|---|---|
boolean |
the boolean value of the system property. |
int hashCode ()
Returns a hash code for this Boolean object.
| Returns | |
|---|---|
int |
the integer 1231 if this object represents
true; returns the integer 1237 if this
object represents false.
|
int hashCode (boolean value)
Returns a hash code for a boolean value; compatible with
Boolean.hashCode().
| Parameters | |
|---|---|
value |
boolean:
the value to hash |
| Returns | |
|---|---|
int |
a hash code value for a boolean value. |
boolean logicalAnd (boolean a,
boolean b)
Returns the result of applying the logical AND operator to the
specified boolean operands.
| Parameters | |
|---|---|
a |
boolean:
the first operand |
b |
boolean:
the second operand |
| Returns | |
|---|---|
boolean |
the logical AND of a and b |
See also:
boolean logicalOr (boolean a,
boolean b)
Returns the result of applying the logical OR operator to the
specified boolean operands.
| Parameters | |
|---|---|
a |
boolean:
the first operand |
b |
boolean:
the second operand |
| Returns | |
|---|---|
boolean |
the logical OR of a and b |
See also:
boolean logicalXor (boolean a,
boolean b)
Returns the result of applying the logical XOR operator to the
specified boolean operands.
| Parameters | |
|---|---|
a |
boolean:
the first operand |
b |
boolean:
the second operand |
| Returns | |
|---|---|
boolean |
the logical XOR of a and b |
See also:
boolean parseBoolean (String s)
Parses the string argument as a boolean. The boolean
returned represents the value true if the string argument
is not null and is equal, ignoring case, to the string
"true".
Example: Boolean.parseBoolean("True") returns true.
Example: Boolean.parseBoolean("yes") returns false.
| Parameters | |
|---|---|
s |
String:
the String containing the boolean
representation to be parsed |
| Returns | |
|---|---|
boolean |
the boolean represented by the string argument |
String toString ()
Returns a String object representing this Boolean's
value. If this object represents the value true,
a string equal to "true" is returned. Otherwise, a
string equal to "false" is returned.
| Returns | |
|---|---|
String |
a string representation of this object. |
String toString (boolean b)
Returns a String object representing the specified
boolean. If the specified boolean is true, then
the string "true" will be returned, otherwise the
string "false" will be returned.
| Parameters | |
|---|---|
b |
boolean:
the boolean to be converted |
| Returns | |
|---|---|
String |
the string representation of the specified boolean |
Boolean valueOf (String s)
Returns a Boolean with a value represented by the
specified string. The Boolean returned represents a
true value if the string argument is not null
and is equal, ignoring case, to the string "true".
| Parameters | |
|---|---|
s |
String:
a string. |
| Returns | |
|---|---|
Boolean |
the Boolean value represented by the string.
|
Boolean valueOf (boolean b)
Returns a Boolean instance representing the specified
boolean value. If the specified boolean value
is true, this method returns Boolean.TRUE;
if it is false, this method returns Boolean.FALSE.
If a new Boolean instance is not required, this method
should generally be used in preference to the constructor
Boolean(boolean), as this method is likely to yield
significantly better space and time performance.
| Parameters | |
|---|---|
b |
boolean:
a boolean value. |
| Returns | |
|---|---|
Boolean |
a Boolean instance representing b. |