The first form is equivalent to attr_reader
. The second form is equivalent to attr_accessor(name)
but deprecated. The last form is equivalent to attr_reader(name)
but deprecated.
Returns an array of the names of the constants accessible in mod. This includes the names of constants in any included modules (example at start of section), unless the inherit parameter is set to false
.
The implementation makes no guarantees about the order in which the constants are yielded.
IO.constants.include?(:SYNC) #=> true IO.constants(false).include?(:SYNC) #=> false
Also see Module::const_defined?
.
With no arguments, sets the default visibility for subsequently defined methods to private. With arguments, sets the named methods to have private visibility. String arguments are converted to symbols.
module Mod def a() end def b() end private def c() end private :a end Mod.private_instance_methods #=> [:a, :c]
Note that to show a private method on RDoc
, use :doc:
.
Truncate to the nearest integer (by default), returning the result as a BigDecimal
.
BigDecimal('3.14159').truncate #=> 3 BigDecimal('8.7').truncate #=> 8 BigDecimal('-9.9').truncate #=> -9
If n is specified and positive, the fractional part of the result has no more than that many digits.
If n is specified and negative, at least that many digits to the left of the decimal point will be 0 in the result.
BigDecimal('3.14159').truncate(3) #=> 3.141 BigDecimal('13345.234').truncate(-2) #=> 13300.0
Returns the numerator.
Rational(7).numerator #=> 7 Rational(7, 1).numerator #=> 7 Rational(9, -4).numerator #=> -9 Rational(-2, -10).numerator #=> 1
Returns the denominator (always positive).
Rational(7).denominator #=> 1 Rational(7, 1).denominator #=> 1 Rational(9, -4).denominator #=> 4 Rational(-2, -10).denominator #=> 5
Returns true
if rat
is less than 0.
Returns rat
truncated (toward zero) to a precision of ndigits
decimal digits (default: 0).
When the precision is negative, the returned value is an integer with at least ndigits.abs
trailing zeros.
Returns a rational when ndigits
is positive, otherwise returns an integer.
Rational(3).truncate #=> 3 Rational(2, 3).truncate #=> 0 Rational(-3, 2).truncate #=> -1 # decimal - 1 2 3 . 4 5 6 # ^ ^ ^ ^ ^ ^ # precision -3 -2 -1 0 +1 +2 Rational('-123.456').truncate(+1).to_f #=> -123.4 Rational('-123.456').truncate(-1) #=> -120
Returns a simpler approximation of the value if the optional argument eps
is given (rat-|eps| <= result <= rat+|eps|), self otherwise.
r = Rational(5033165, 16777216) r.rationalize #=> (5033165/16777216) r.rationalize(Rational('0.01')) #=> (3/10) r.rationalize(Rational('0.1')) #=> (1/3)
Returns true if the date is Sunday.
Returns true if the date is Monday.
Returns true if the date is Tuesday.
Returns true if the date is Wednesday.
Returns true if the date is Thursday.
Returns true if the date is Friday.
Returns the Julian day number denoting the day of calendar reform.
Date.new(2001,2,3).start #=> 2299161.0 Date.new(2001,2,3,Date::GREGORIAN).start #=> -Infinity
This method is equivalent to new_start
(Date::ITALY
).
Creates a new Time
object with the value given by time
, the given number of seconds_with_frac
, or seconds
and microseconds_with_frac
since the Epoch. seconds_with_frac
and microseconds_with_frac
can be an Integer
, Float
, Rational
, or other Numeric
. non-portable feature allows the offset to be negative on some systems.
If a numeric argument is given, the result is in local time.
Time.at(0) #=> 1969-12-31 18:00:00 -0600 Time.at(Time.at(0)) #=> 1969-12-31 18:00:00 -0600 Time.at(946702800) #=> 1999-12-31 23:00:00 -0600 Time.at(-284061600) #=> 1960-12-31 00:00:00 -0600 Time.at(946684800.2).usec #=> 200000 Time.at(946684800, 123456.789).nsec #=> 123456789 Time.at(946684800, 123456789, :nsec).nsec #=> 123456789
Returns the day of the month (1..n) for time.
t = Time.now #=> 2007-11-19 08:27:03 -0600 t.day #=> 19 t.mday #=> 19