java.lang.Object | ||
↳ | java.lang.Number | |
↳ | android.util.Rational |
An immutable data type representation a rational number.
Contains a pair of int
s representing the numerator and denominator of a
Rational number.
Fields | |||||||||||
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NEGATIVE_INFINITY |
Constant for the negative infinity value of the Rational type.
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NaN |
Constant for the Not-a-Number (NaN) value of the Rational type.
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POSITIVE_INFINITY |
Constant for the positive infinity value of the Rational type.
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ZERO |
Constant for the zero value of the Rational type.
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Public Constructors | |||||||||||
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Create a |
Public Methods | |||||||||||
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Compare this rational to the specified rational to determine their natural order.
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Returns the value of the specified number as a
double .
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Compare this Rational to another object and see if they are equal. | |||||||||||
Returns the value of the specified number as a
float .
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Gets the denominator of the rational
The denominator may return | |||||||||||
Gets the numerator of the rational.
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Returns an integer hash code for this object.
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Returns the value of the specified number as a
int .
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Indicates whether this rational represents a finite value.
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Indicates whether this rational represents an infinite value.
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Indicates whether this rational is a Not-a-Number (NaN) value.
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Indicates whether this rational represents a zero value.
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Returns the value of the specified number as a
long .
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Parses the specified string as a rational value.
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Returns the value of the specified number as a
short .
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Return a string representation of this rational, e.g.
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[Expand]
Inherited Methods | |||||||||||
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From class
java.lang.Number
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From class
java.lang.Object
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From interface
java.lang.Comparable
|
Constant for the negative infinity value of the Rational
type.
Equivalent to constructing a new rational with a negative numerator and a denominator
equal to 0
.
Constant for the Not-a-Number (NaN) value of the Rational
type.
A NaN
value is considered to be equal to itself (that is NaN.equals(NaN)
will return true
; it is always greater than any non-NaN
value (that is
NaN.compareTo(notNaN)
will return a number greater than 0
).
Equivalent to constructing a new rational with both the numerator and denominator
equal to 0
.
Constant for the positive infinity value of the Rational
type.
Equivalent to constructing a new rational with a positive numerator and a denominator
equal to 0
.
Constant for the zero value of the Rational
type.
Equivalent to constructing a new rational with a numerator equal to 0
and
any non-zero denominator.
Create a Rational
with a given numerator and denominator.
The signs of the numerator and the denominator may be flipped such that the denominator
is always positive. Both the numerator and denominator will be converted to their reduced
forms (see equals(Object)
for more details).
For example,
2/4
will be reduced to 1/2
.
1/-1
will be flipped to -1/1
5/0
will be reduced to 1/0
0/5
will be reduced to 0/1
numerator | the numerator of the rational |
---|---|
denominator | the denominator of the rational |
Compare this rational to the specified rational to determine their natural order.
NaN
is considered to be equal to itself and greater than all other
Rational
values. Otherwise, if the objects are not equal
, then
the following rules apply:
another | the rational to be compared |
---|
NullPointerException | if another was null
|
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Returns the value of the specified number as a double
.
The double
is calculated by converting both the numerator and denominator
to a double
; then returning the result of dividing the numerator by the
denominator.
double
.
Compare this Rational to another object and see if they are equal.
A Rational object can only be equal to another Rational object (comparing against any
other type will return false
).
A Rational object is considered equal to another Rational object if and only if one of the following holds:
NaN
A reduced form of a Rational is calculated by dividing both the numerator and the denominator by their greatest common divisor.
(new Rational(1, 2)).equals(new Rational(1, 2)) == true // trivially true
(new Rational(2, 3)).equals(new Rational(1, 2)) == false // trivially false
(new Rational(1, 2)).equals(new Rational(2, 4)) == true // true after reduction
(new Rational(0, 0)).equals(new Rational(0, 0)) == true // NaN.equals(NaN)
(new Rational(1, 0)).equals(new Rational(5, 0)) == true // both are +infinity
(new Rational(1, 0)).equals(new Rational(-1, 0)) == false // +infinity != -infinity
obj | a reference to another object |
---|
Returns the value of the specified number as a float
.
The float
is calculated by converting both the numerator and denominator
to a float
; then returning the result of dividing the numerator by the
denominator.
float
.
Gets the denominator of the rational
The denominator may return 0
, in which case the rational may represent
positive infinity (if the numerator was positive), negative infinity (if the numerator
was negative), or NaN
(if the numerator was 0
).
The denominator will always return 1
if the numerator is 0
.
Gets the numerator of the rational.
The numerator will always return 1
if this rational represents
infinity (that is, the denominator is 0
).
Returns an integer hash code for this object. By contract, any two
objects for which equals(Object)
returns true
must return
the same hash code value. This means that subclasses of Object
usually override both methods or neither method.
Note that hash values must not change over time unless information used in equals comparisons also changes.
See Writing a correct
hashCode
method
if you intend implementing your own hashCode
method.
Returns the value of the specified number as a int
.
Finite
rationals are converted to an int
value
by dividing the numerator by the denominator; conversion for non-finite values happens
identically to casting a floating point value to an int
, in particular:
int
.
Indicates whether this rational represents a finite value.
A finite value occurs when the denominator is not 0
; in other words
the rational is neither infinity or NaN
.
true
if this rational is a (positive or negative) infinite value;
false
if this is a finite number value (or NaN
)
Indicates whether this rational represents an infinite value.
An infinite value occurs when the denominator is 0
(but the numerator is not).
true
if this rational is a (positive or negative) infinite value;
false
if this is a finite number value (or NaN
)
Indicates whether this rational is a Not-a-Number (NaN) value.
A NaN
value occurs when both the numerator and the denominator are 0
.
true
if this rational is a Not-a-Number (NaN) value;
false
if this is a (potentially infinite) number value
Indicates whether this rational represents a zero value.
A zero value is a finite
rational with a numerator of 0
.
true
if this rational is finite zero value;
false
otherwise
Returns the value of the specified number as a long
.
Finite
rationals are converted to an long
value
by dividing the numerator by the denominator; conversion for non-finite values happens
identically to casting a floating point value to a long
, in particular:
long
.
Parses the specified string as a rational value.
The ASCII characters \
u003a
(':') and
\
u002f
('/') are recognized as separators between
the numerator and denumerator.
For any Rational r
: Rational.parseRational(r.toString()).equals(r)
.
However, the method also handles rational numbers expressed in the
following forms:
"num/
den" or
"num:
den" => new Rational(num, den);
,
where num and den are string integers potentially
containing a sign, such as "-10", "+7" or "5".
Rational.parseRational("3:+6").equals(new Rational(1, 2)) == true
Rational.parseRational("-3/-6").equals(new Rational(1, 2)) == true
Rational.parseRational("4.56") => throws NumberFormatException
string | the string representation of a rational value. |
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string
.NumberFormatException | if string cannot be parsed
as a rational value. |
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NullPointerException | if string was null
|
Returns the value of the specified number as a short
.
Finite
rationals are converted to a short
value
identically to intValue()
; the int
result is then truncated to a
short
before returning the value.
short
.
Return a string representation of this rational, e.g. "1/2"
.
The following rules of conversion apply:
NaN
values will return "NaN"
"Infinity"
"-Infinity"
"numerator/denominator"
where numerator
and denominator
are substituted with the appropriate numerator and denominator
values.