Added in API level 1

Number

public abstract class Number
extends Object implements Serializable

java.lang.Object
   ↳ java.lang.Number
AtomicInteger An int value that may be updated atomically. 
AtomicLong A long value that may be updated atomically. 
BigDecimal Immutable, arbitrary-precision signed decimal numbers. 
BigInteger Immutable arbitrary-precision integers. 
Byte The Byte class wraps a value of primitive type byte in an object. 
Double The Double class wraps a value of the primitive type double in an object. 
DoubleAccumulator One or more variables that together maintain a running double value updated using a supplied function. 
DoubleAdder One or more variables that together maintain an initially zero double sum. 
Float The Float class wraps a value of primitive type float in an object. 
Half

The Half class is a wrapper and a utility class to manipulate half-precision 16-bit IEEE 754 floating point data types (also called fp16 or binary16). 

Integer The Integer class wraps a value of the primitive type int in an object. 
Long The Long class wraps a value of the primitive type long in an object. 
LongAccumulator One or more variables that together maintain a running long value updated using a supplied function. 
LongAdder One or more variables that together maintain an initially zero long sum. 
Rational

An immutable data type representation a rational number. 

Short The Short class wraps a value of primitive type short in an object. 


The abstract class Number is the superclass of platform classes representing numeric values that are convertible to the primitive types byte, double, float, int, long, and short. The specific semantics of the conversion from the numeric value of a particular Number implementation to a given primitive type is defined by the Number implementation in question. For platform classes, the conversion is often analogous to a narrowing primitive conversion or a widening primitive conversion as defined in The Java Language Specification for converting between primitive types. Therefore, conversions may lose information about the overall magnitude of a numeric value, may lose precision, and may even return a result of a different sign than the input. See the documentation of a given Number implementation for conversion details.

Summary

Public constructors

Number()

Constructor for subclasses to call.

Public methods

byte byteValue()

Returns the value of the specified number as a byte.

abstract double doubleValue()

Returns the value of the specified number as a double.

abstract float floatValue()

Returns the value of the specified number as a float.

abstract int intValue()

Returns the value of the specified number as an int.

abstract long longValue()

Returns the value of the specified number as a long.

short shortValue()

Returns the value of the specified number as a short.

Inherited methods

Object clone()

Creates and returns a copy of this object.

boolean equals(Object obj)

Indicates whether some other object is "equal to" this one.

void finalize()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

final Class<?> getClass()

Returns the runtime class of this Object.

int hashCode()

Returns a hash code value for the object.

final void notify()

Wakes up a single thread that is waiting on this object's monitor.

final void notifyAll()

Wakes up all threads that are waiting on this object's monitor.

String toString()

Returns a string representation of the object.

final void wait(long timeoutMillis, int nanos)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void wait(long timeoutMillis)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void wait()

Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Public constructors

Number

Added in API level 1
public Number ()

Constructor for subclasses to call.

Public methods

byteValue

Added in API level 1
public byte byteValue ()

Returns the value of the specified number as a byte.

Implementation Requirements:
  • The default implementation returns the result of intValue() cast to a byte.
Returns
byte the numeric value represented by this object after conversion to type byte.

doubleValue

Added in API level 1
public abstract double doubleValue ()

Returns the value of the specified number as a double.

Returns
double the numeric value represented by this object after conversion to type double.

floatValue

Added in API level 1
public abstract float floatValue ()

Returns the value of the specified number as a float.

Returns
float the numeric value represented by this object after conversion to type float.

intValue

Added in API level 1
public abstract int intValue ()

Returns the value of the specified number as an int.

Returns
int the numeric value represented by this object after conversion to type int.

longValue

Added in API level 1
public abstract long longValue ()

Returns the value of the specified number as a long.

Returns
long the numeric value represented by this object after conversion to type long.

shortValue

Added in API level 1
public short shortValue ()

Returns the value of the specified number as a short.

Implementation Requirements:
  • The default implementation returns the result of intValue() cast to a short.
Returns
short the numeric value represented by this object after conversion to type short.