public final class Boolean extends Object implements Serializable, Comparable<Boolean>
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
.
Modifier and Type | Field and Description |
---|---|
static Boolean |
FALSE
The
Boolean object corresponding to the primitive
value false . |
static Boolean |
TRUE
The
Boolean object corresponding to the primitive
value true . |
static Class<Boolean> |
TYPE
The Class object representing the primitive type boolean.
|
Constructor and Description |
---|
Boolean(boolean value)
Allocates a
Boolean object representing the
value argument. |
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" . |
Modifier and Type | Method and Description |
---|---|
boolean |
booleanValue()
Returns the value of this
Boolean object as a boolean
primitive. |
static int |
compare(boolean x,
boolean y)
Compares two
boolean values. |
int |
compareTo(Boolean b)
Compares this
Boolean instance with another. |
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. |
static 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" . |
int |
hashCode()
Returns a hash code for this
Boolean object. |
static boolean |
parseBoolean(String s)
Parses the string argument as a boolean.
|
String |
toString()
Returns a
String object representing this Boolean's
value. |
static String |
toString(boolean b)
Returns a
String object representing the specified
boolean. |
static Boolean |
valueOf(boolean b)
Returns a
Boolean instance representing the specified
boolean value. |
static Boolean |
valueOf(String s)
Returns a
Boolean with a value represented by the
specified string. |
public static final Boolean TRUE
Boolean
object corresponding to the primitive
value true
.public static final Boolean FALSE
Boolean
object corresponding to the primitive
value false
.public Boolean(boolean value)
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.
value
- the value of the Boolean
.public Boolean(String s)
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
.
s
- the string to be converted to a Boolean
.public static boolean parseBoolean(String s)
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
.
s
- the String
containing the boolean
representation to be parsedpublic boolean booleanValue()
Boolean
object as a boolean
primitive.boolean
value of this object.public static Boolean valueOf(boolean b)
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.b
- a boolean value.Boolean
instance representing b
.public static Boolean valueOf(String s)
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"
.s
- a string.Boolean
value represented by the string.public static String toString(boolean b)
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.b
- the boolean to be convertedboolean
public String toString()
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.public int hashCode()
Boolean
object.hashCode
in class Object
1231
if this object represents
true
; returns the integer 1237
if this
object represents false
.Object.equals(java.lang.Object)
,
System.identityHashCode(java.lang.Object)
public boolean equals(Object obj)
true
if and only if the argument is not
null
and is a Boolean
object that
represents the same boolean
value as this object.equals
in class Object
obj
- the object to compare with.true
if the Boolean objects represent the
same value; false
otherwise.Object.hashCode()
,
HashMap
public static boolean getBoolean(String name)
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.
name
- the system property name.boolean
value of the system property.System.getProperty(java.lang.String)
,
System.getProperty(java.lang.String, java.lang.String)
public int compareTo(Boolean b)
Boolean
instance with another.compareTo
in interface Comparable<Boolean>
b
- the Boolean
instance to be comparedNullPointerException
- if the argument is null
Comparable
public static int compare(boolean x, boolean y)
boolean
values.
The value returned is identical to what would be returned by:
Boolean.valueOf(x).compareTo(Boolean.valueOf(y))
x
- the first boolean
to comparey
- the second boolean
to compare0
if x == y
;
a value less than 0
if !x && y
; and
a value greater than 0
if x && !y
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For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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