Boolean (Java 2 Platform SE 5.0) (original) (raw)

java.lang

Class Boolean

java.lang.Object java.lang.Boolean

All Implemented Interfaces:

Serializable, Comparable<Boolean>

public final class Boolean

extends Object

implements Serializable, Comparable<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.

Since:

JDK1.0

See Also:

Serialized Form

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

public static final Class<Boolean> TYPE

The Class object representing the primitive type boolean.

Since:

JDK1.1

Boolean

public 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 factoryvalueOf(boolean) is generally a better choice. It is likely to yield significantly better space and time performance.

Parameters:

value - the value of the Boolean.

Boolean

public 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 - the string to be converted to a Boolean.

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".

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

public static Boolean valueOf(String s)

Returns a Boolean with a value represented by the specified String. 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.valueOf("True") returns true.
Example: Boolean.valueOf("yes") returns false.

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

public 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.

Overrides:

[toString](../../java/lang/Object.html#toString%28%29) in class [Object](../../java/lang/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](../../java/lang/Object.html#hashCode%28%29) in class [Object](../../java/lang/Object.html "class in java.lang")

Returns:

the integer 1231 if this object represents true; returns the integer 1237 if this object represents false.

See Also:

Object.equals(java.lang.Object), Hashtable

equals

public 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.

Overrides:

[equals](../../java/lang/Object.html#equals%28java.lang.Object%29) in class [Object](../../java/lang/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(), Hashtable

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 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 - the system property name.

Returns:

the boolean value of the system property.

See Also:

System.getProperty(java.lang.String), [System.getProperty(java.lang.String, java.lang.String)](../../java/lang/System.html#getProperty%28java.lang.String, java.lang.String%29)

compareTo

public int compareTo(Boolean b)

Compares this Boolean instance with another.

Specified by:

[compareTo](../../java/lang/Comparable.html#compareTo%28T%29) in interface [Comparable](../../java/lang/Comparable.html "interface in java.lang")<[Boolean](../../java/lang/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](../../java/lang/NullPointerException.html "class in java.lang") - if the argument is null

Since:

1.5

See Also:

Comparable

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For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

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