Since int
is already an Integer
, this always returns true
.
Returns true if self
is a prime number, else returns false. Not recommended for very big integers (> 10**23).
Returns int
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 self
when ndigits
is zero or positive.
1.truncate #=> 1 1.truncate(2) #=> 1 18.truncate(-1) #=> 10 (-18).truncate(-1) #=> -10
Returns the remainder after dividing int
by numeric
.
x.remainder(y)
means x-y*(x/y).truncate
.
5.remainder(3) #=> 2 -5.remainder(3) #=> -2 5.remainder(-3) #=> 2 -5.remainder(-3) #=> -2 5.remainder(1.5) #=> 0.5
See Numeric#divmod
.
Returns a string containing the place-value representation of int
with radix base
(between 2 and 36).
12345.to_s #=> "12345" 12345.to_s(2) #=> "11000000111001" 12345.to_s(8) #=> "30071" 12345.to_s(10) #=> "12345" 12345.to_s(16) #=> "3039" 12345.to_s(36) #=> "9ix" 78546939656932.to_s(36) #=> "rubyrules"
Returns 1.
Returns a complex object which denotes the given rectangular form.
Complex.rectangular(1, 2) #=> (1+2i)
Returns the imaginary part.
Complex(7).imaginary #=> 0 Complex(9, -4).imaginary #=> -4
Returns the angle part of its polar form.
Complex.polar(3, Math::PI/2).arg #=> 1.5707963267948966
Returns the denominator (lcm of both denominator - real and imag).
See numerator.
Returns the value as a string for inspection.
Complex(2).inspect #=> "(2+0i)" Complex('-8/6').inspect #=> "((-4/3)+0i)" Complex('1/2i').inspect #=> "(0+(1/2)*i)" Complex(0, Float::INFINITY).inspect #=> "(0+Infinity*i)" Complex(Float::NAN, Float::NAN).inspect #=> "(NaN+NaN*i)"
Returns true
if cmp
‘s real and imaginary parts are both finite numbers, otherwise returns false
.
Always returns the string “nil”.
Returns zero.
Returns 0 if the value is positive, pi otherwise.
Returns an array; [num, 0].
Returns true
if num
is a finite number, otherwise returns false
.
Returns num
truncated (toward zero) to a precision of ndigits
decimal digits (default: 0).
Numeric
implements this by converting its value to a Float
and invoking Float#truncate
.
Invokes the given block with the sequence of numbers starting at num
, incremented by step
(defaulted to 1
) on each call.
The loop finishes when the value to be passed to the block is greater than limit
(if step
is positive) or less than limit
(if step
is negative), where limit
is defaulted to infinity.
In the recommended keyword argument style, either or both of step
and limit
(default infinity) can be omitted. In the fixed position argument style, zero as a step (i.e. num.step(limit, 0)
) is not allowed for historical compatibility reasons.
If all the arguments are integers, the loop operates using an integer counter.
If any of the arguments are floating point numbers, all are converted to floats, and the loop is executed floor(n + n*Float::EPSILON) + 1 times, where n = (limit - num)/step.
Otherwise, the loop starts at num
, uses either the less-than (<
) or greater-than (>
) operator to compare the counter against limit
, and increments itself using the +
operator.
If no block is given, an Enumerator
is returned instead. Especially, the enumerator is an Enumerator::ArithmeticSequence
if both limit
and step
are kind of Numeric
or nil
.
For example:
p 1.step.take(4) p 10.step(by: -1).take(4) 3.step(to: 5) {|i| print i, " " } 1.step(10, 2) {|i| print i, " " } Math::E.step(to: Math::PI, by: 0.2) {|f| print f, " " }
Will produce:
[1, 2, 3, 4] [10, 9, 8, 7] 3 4 5 1 3 5 7 9 2.718281828459045 2.9182818284590453 3.118281828459045
Returns the denominator (always positive).
Returns 0 if the value is positive, pi otherwise.
Returns float
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 floating point number when ndigits
is positive, otherwise returns an integer.
2.8.truncate #=> 2 (-2.8).truncate #=> -2 1.234567.truncate(2) #=> 1.23 34567.89.truncate(-2) #=> 34500
Note that the limited precision of floating point arithmetic might lead to surprising results:
(0.3 / 0.1).truncate #=> 2 (!)