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 parsed
public 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 converted
boolean
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 compared
NullPointerException
- 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 compare
y
- the second boolean
to compare
0
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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