5, Groovy Math
l Groovy supports all Java Math classes and operations
l In order to make MATH operations in the script, the Groovy Math model supports a literary MATH operation.
l Default computing is used as a precise decimal (BigDecimal), such as:
1.1 0.1 == 1.2
Returns True, not False (not using float or double in Java)
(1) Digital text representation
l Groovy's decimal text represents an instance of java.math.bigDecimal, not a floating point type (Float or Double)
l Float and Double can create the suffix (f and d) method later
l The decimal form of the decimal is also supported, such as 12.3e-23
l hexadecimal and octal support, hexadecimal prefix 0x, octal prefix 0
l Integer types can be created using the suffix (i, l, and g) methods later, if not specifying the size of the size according to the value
l Digital type suffix text representation
_Type_
_SUFFIX_
_Biginteger_
G
_Long_
L
_INTEGER_
I
_BIGDECIMAL_
(default)
_Double_
Di
_Float_
Fly
l example:
Assert 42i == New Integer ("42");
Assert 123L == New long ("123");
Assert 2147483648 == New long ("2147483648"); // long type used, value to large for anteger
Assert 456g == New java.math.biginteger ("456");
Assert 123.45 == New java.math.bigDecimal ("123.45"); // default bigdecimal type used
Assert 1.200065D == New Double ("1.200065");
Assert 1.234F == New float ("1.234");
askERT 1.23E23D == New Double ("1.23E23");
(2) Math operation
L Groovy's Math implementation is very close to the practice of Java 1.5 BigDecimal Math model
l Java.lang.Number includes binary operations (except for division), in addition to the following table automatically converts parameter types
_BIGDECIMAL_
_Biginteger_
_Double_
_Float_
_Long_
_INTEGER_
_BIGDECIMAL_
BigDecimal
BigDecimal
Double
Double
BigDecimal
BigDecimal
_Biginteger_
BigDecimal
Biginteger
Double
Double
Biginteger
Biginteger
_Double_
Double
Double
Double
Doubledouble
Double
_Float_
Double
Double
Double
Double
Double
Double
_Long_
BigDecimal
Biginteger
Double
Double
Long
Long
_INTEGER_
BigDecimal
Biginteger
Double
Double
Long
Integer
l Note: Byte, Character, Short as an Integer type
(3) division
L Solution Operations "/" and "/ =" When there is a float or double type in the operand, the result is a double type; other cases, the result is a BigDecimal type
l BigDecimal type operation will do this:
BigDecimal.divide (BigDecimal Right,
Where
l example:
1/2 == New java.math.bigDecimal ("0.5");
1/3 == New java.math.bigdecimal ("0.333333333");
2/3 == New java.math.bigdecimal ("0.666666667");
l Integer division uses "/" and "/ =" operation, return to integer type
l Since "/" is the escape character in Java, use the need to escape in the string
"x = 8 // 3"
(4) Digital text representation syntax
IntegerLiteral:
Base10integerliteral
Hexintegerliteral
Octalintegerliteral
Base10integerliteral:
Base10Numeral IntegertypeSuffix (optional)
Hexintegerliteral:
HEXNUMERALALTYPESUFFIX (OPTIONAL)
Octalintegerliteral:
OctalNumeral IntegertypeSuffix (optional)
IntegertypeSuffix: One of
I I l L g g
Base10Numeral:
0
Nonzerodigit Digits (Optional)
Digits:
Digit
DIGITS DIGIT
DIGIT:
0
Nonzerodigit
Nonzerodigit: one of
/ 1 2 3 4 5 6 7 8 9
HEXNUMERAL:
0 x hexdigits
0 x hexdigits
HEXDIGITS:
HEXDIGIT
HEXDIGIT HEXDIGITS
HEXDIGIT: One of
0 1 2 3 4 5 6 7 8 9 A b C D e f A B C D e f
OctalNumeral:
0 Octaldigits
Octaldigits:
Octaldigit
Octaldigit Octaldigits
Octaldigit: one of
0 1 2 3 4 5 6 7
DecimalPointLiteral:
Digits. Digits ExponentPart (optional) DecimalTypeSuffix (optional)
DIGITS ExponentPart (optional) DECIMALTYPESUFFIX (OPTIONAL) DIGITS ExponentPart DecalogPArthPart DecalogPASUFFIX (Optional)
DIGITS ExponentPart (optional) DecimalTypeSuffix (Optional)
ExponentPart:
ExponentIndicator Signedinteger
Exponentindicator: One of
e e
Signedinteger:
Signopt Digits
Sign: One of Of
-
DecimalTypeSuffix: One of
F f D D g g
