Boolean (Java SE 17 & JDK 17) (original) (raw)

All Implemented Interfaces:

[Serializable](../io/Serializable.html "interface in java.io"), [Comparable](Comparable.html "interface in java.lang")<[Boolean](Boolean.html "class in java.lang")>, [Constable](constant/Constable.html "interface in java.lang.constant")

The Boolean class wraps a value of the primitive typeboolean in an object. An object of typeBoolean contains a single field whose type isboolean.

In addition, this class provides many methods for converting a boolean to a String and aString to a boolean, as well as other constants and methods useful when dealing with aboolean.

This is a value-based class; programmers should treat instances that areequal as interchangeable and should not use instances for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail.

Since:

1.0

See Also:

• Serialized Form

• Field Summary

Fields
The Boolean object corresponding to the primitive value false.
The Boolean object corresponding to the primitive value true.
The Class object representing the primitive type boolean.

• Constructor Summary

Constructors
[Boolean](#%3Cinit%3E%28boolean%29)(boolean value)
Deprecated, for removal: This API element is subject to removal in a future version.
Deprecated, for removal: This API element is subject to removal in a future version.

• Method Summary

boolean
Returns the value of this Boolean object as a boolean primitive.
static int
[compare](#compare%28boolean,boolean%29)(boolean x, boolean y)
Compares two boolean values.
int
Compares this Boolean instance with another.
Returns an Optional containing the nominal descriptor for this instance.
boolean
Returns true if and only if the argument is notnull and is a Boolean object that represents the same boolean value as this object.
static boolean
Returns true if and only if the system property named by the argument exists and is equal to, ignoring case, the string "true".
int
[hashCode](#hashCode%28%29)()
Returns a hash code for this Boolean object.
static int
[hashCode](#hashCode%28boolean%29)(boolean value)
Returns a hash code for a boolean value; compatible withBoolean.hashCode().
static boolean
[logicalAnd](#logicalAnd%28boolean,boolean%29)(boolean a, boolean b)
Returns the result of applying the logical AND operator to the specified boolean operands.
static boolean
[logicalOr](#logicalOr%28boolean,boolean%29)(boolean a, boolean b)
Returns the result of applying the logical OR operator to the specified boolean operands.
static boolean
[logicalXor](#logicalXor%28boolean,boolean%29)(boolean a, boolean b)
Returns the result of applying the logical XOR operator to the specified boolean operands.
static boolean
Parses the string argument as a boolean.
[toString](#toString%28%29)()
Returns a String object representing this Boolean's value.
[toString](#toString%28boolean%29)(boolean b)
Returns a String object representing the specified boolean.
[valueOf](#valueOf%28boolean%29)(boolean b)
Returns a Boolean instance representing the specifiedboolean value.
Returns a Boolean with a value represented by the specified string.

• Field Details

  • TRUE

  public static final Boolean TRUE
  The Boolean object corresponding to the primitive value true.

  • FALSE

  public static final Boolean FALSE
  The Boolean object corresponding to the primitive value false.

  • TYPE

  The Class object representing the primitive type boolean.
  Since:
  1.1

• Constructor Details

  • Boolean

  Deprecated, for removal: This API element is subject to removal in a future version.
  Allocates a Boolean object representing thevalue argument.
  Parameters:
  value - the value of the Boolean.

  • Boolean

  Deprecated, for removal: This API element is subject to removal in a future version.
  Allocates a Boolean object representing the valuetrue if the string argument is not null and is equal, ignoring case, to the string "true". Otherwise, allocates a Boolean object representing the value false.
  Parameters:
  s - the string to be converted to a Boolean.

• Method Details

  • parseBoolean

  public static 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". Otherwise, a false value is returned, including for a null argument.
  Example: Boolean.parseBoolean("True") returns true.
  Example: Boolean.parseBoolean("yes") returns false.
  Parameters:
  s - the String containing the boolean representation to be parsed
  Returns:
  the boolean represented by the string argument
  Since:
  1.5

  • booleanValue

  public boolean booleanValue()
  Returns the value of this Boolean object as a boolean primitive.
  Returns:
  the primitive boolean value of this object.

  • valueOf

  public static Boolean valueOf(boolean b)
  Returns a Boolean instance representing the specifiedboolean 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 constructorBoolean(boolean), as this method is likely to yield significantly better space and time performance.
  Parameters:
  b - a boolean value.
  Returns:
  a Boolean instance representing b.
  Since:
  1.4

  • valueOf

  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". Otherwise, a false value is returned, including for a null argument.
  Parameters:
  s - a string.
  Returns:
  the Boolean value represented by the string.

  • toString

  public static 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 - the boolean to be converted
  Returns:
  the string representation of the specified boolean
  Since:
  1.4

  • 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.
  Overrides:
  [toString](Object.html#toString%28%29) in class [Object](Object.html "class in java.lang")
  Returns:
  a string representation of this object.

  • hashCode

  public int hashCode()
  Returns a hash code for this Boolean object.
  Overrides:
  [hashCode](Object.html#hashCode%28%29) in class [Object](Object.html "class in java.lang")
  Returns:
  the integer 1231 if this object representstrue; returns the integer 1237 if this object represents false.
  See Also:
  * Object.equals(java.lang.Object)
  * System.identityHashCode(java.lang.Object)

  • hashCode

  public static int hashCode(boolean value)
  Returns a hash code for a boolean value; compatible withBoolean.hashCode().
  Parameters:
  value - the value to hash
  Returns:
  a hash code value for a boolean value.
  Since:
  1.8

  • equals

  public boolean equals(Object obj)
  Returns true if and only if the argument is notnull and is a Boolean object that represents the same boolean value as this object.
  Overrides:
  [equals](Object.html#equals%28java.lang.Object%29) in class [Object](Object.html "class in java.lang")
  Parameters:
  obj - the object to compare with.
  Returns:
  true if the Boolean objects represent the same value; false otherwise.
  See Also:
  * Object.hashCode()
  * HashMap

  • getBoolean

  public static boolean getBoolean(String name)
  Returns true if and only if the system property named by the argument exists and is equal to, ignoring case, the string "true". 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 - the system property name.
  Returns:
  the boolean value of the system property.
  Throws:
  [SecurityException](SecurityException.html "class in java.lang") - for the same reasons asSystem.getProperty
  See Also:
  * System.getProperty(java.lang.String)
  * System.getProperty(java.lang.String, java.lang.String)

  • compareTo

  public int compareTo(Boolean b)
  Compares this Boolean instance with another.
  Specified by:
  [compareTo](Comparable.html#compareTo%28T%29) in interface [Comparable](Comparable.html "interface in java.lang")<[Boolean](Boolean.html "class in java.lang")>
  Parameters:
  b - the Boolean instance to be compared
  Returns:
  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](NullPointerException.html "class in java.lang") - if the argument is null
  Since:
  1.5
  See Also:
  * Comparable

  • compare

  public static 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 - the first boolean to compare
  y - the second boolean to compare
  Returns:
  the value 0 if x == y; a value less than 0 if !x && y; and a value greater than 0 if x && !y
  Since:
  1.7

  • logicalAnd

  public static boolean logicalAnd(boolean a, boolean b)
  Returns the result of applying the logical AND operator to the specified boolean operands.
  Parameters:
  a - the first operand
  b - the second operand
  Returns:
  the logical AND of a and b
  Since:
  1.8
  See Also:
  * BinaryOperator

  • logicalOr

  public static boolean logicalOr(boolean a, boolean b)
  Returns the result of applying the logical OR operator to the specified boolean operands.
  Parameters:
  a - the first operand
  b - the second operand
  Returns:
  the logical OR of a and b
  Since:
  1.8
  See Also:
  * BinaryOperator

  • logicalXor

  public static boolean logicalXor(boolean a, boolean b)
  Returns the result of applying the logical XOR operator to the specified boolean operands.
  Parameters:
  a - the first operand
  b - the second operand
  Returns:
  the logical XOR of a and b
  Since:
  1.8
  See Also:
  * BinaryOperator

  • describeConstable

  Returns an Optional containing the nominal descriptor for this instance.
  Specified by:
  [describeConstable](constant/Constable.html#describeConstable%28%29) in interface [Constable](constant/Constable.html "interface in java.lang.constant")
  Returns:
  an Optional describing the Boolean instance
  Since:
  15