Returns a new Array containing all non-nil elements from self:
a = [nil, 0, nil, 1, nil, 2, nil] a.compact # => [0, 1, 2]
Removes all nil elements from self.
Returns self if any elements removed, otherwise nil.
Returns a new Array containing all but the first n element of self, where n is a non-negative Integer; does not modify self.
Examples:
a = [0, 1, 2, 3, 4, 5] a.drop(0) # => [0, 1, 2, 3, 4, 5] a.drop(1) # => [1, 2, 3, 4, 5] a.drop(2) # => [2, 3, 4, 5]
Returns true if no element of self meet a given criterion.
With no block given and no argument, returns true if self has no truthy elements, false otherwise:
[nil, false].none? # => true [nil, 0, false].none? # => false [].none? # => true
With a block given and no argument, calls the block with each element in self; returns true if the block returns no truthy value, false otherwise:
[0, 1, 2].none? {|element| element > 3 } # => true [0, 1, 2].none? {|element| element > 1 } # => false
If argument obj is given, returns true if obj.=== no element, false otherwise:
['food', 'drink'].none?(/bar/) # => true ['food', 'drink'].none?(/foo/) # => false [].none?(/foo/) # => true [0, 1, 2].none?(3) # => true [0, 1, 2].none?(1) # => false
Related: Enumerable#none?
Returns true if exactly one element of self meets a given criterion.
With no block given and no argument, returns true if self has exactly one truthy element, false otherwise:
[nil, 0].one? # => true [0, 0].one? # => false [nil, nil].one? # => false [].one? # => false
With a block given and no argument, calls the block with each element in self; returns true if the block a truthy value for exactly one element, false otherwise:
[0, 1, 2].one? {|element| element > 0 } # => false [0, 1, 2].one? {|element| element > 1 } # => true [0, 1, 2].one? {|element| element > 2 } # => false
If argument obj is given, returns true if obj.=== exactly one element, false otherwise:
[0, 1, 2].one?(0) # => true [0, 0, 1].one?(0) # => false [1, 1, 2].one?(0) # => false ['food', 'drink'].one?(/bar/) # => false ['food', 'drink'].one?(/foo/) # => true [].one?(/foo/) # => false
Related: Enumerable#one?
Formats each element in self into a binary string; returns that string. See Packed Data.
Returns an array with both a numeric and a int represented as Integer objects or Float objects.
This is achieved by converting numeric to an Integer or a Float.
A TypeError is raised if the numeric is not an Integer or a Float type.
(0x3FFFFFFFFFFFFFFF+1).coerce(42) #=> [42, 4611686018427387904]
Calls the given block with each integer value from self up to limit; returns self:
a = [] 5.upto(10) {|i| a << i } # => 5 a # => [5, 6, 7, 8, 9, 10] a = [] -5.upto(0) {|i| a << i } # => -5 a # => [-5, -4, -3, -2, -1, 0] 5.upto(4) {|i| fail 'Cannot happen' } # => 5
With no block given, returns an Enumerator.
Calls the given block self times with each integer in (0..self-1):
a = [] 5.times {|i| a.push(i) } # => 5 a # => [0, 1, 2, 3, 4]
With no block given, returns an Enumerator.
Returns the remainder after dividing self by other.
Examples:
11.remainder(4) # => 3 11.remainder(-4) # => 3 -11.remainder(4) # => -3 -11.remainder(-4) # => -3 12.remainder(4) # => 0 12.remainder(-4) # => 0 -12.remainder(4) # => 0 -12.remainder(-4) # => 0 13.remainder(4.0) # => 1.0 13.remainder(Rational(4, 1)) # => (1/1)
Since int is already an Integer, this always returns true.
Returns true if int has a zero value.
Returns self.
Returns a complex object which denotes the given rectangular form.
Complex.rectangular(1, 2) #=> (1+2i)
Returns a complex object which denotes the given polar form.
Complex.polar(3, 0) #=> (3.0+0.0i) Complex.polar(3, Math::PI/2) #=> (1.836909530733566e-16+3.0i) Complex.polar(3, Math::PI) #=> (-3.0+3.673819061467132e-16i) Complex.polar(3, -Math::PI/2) #=> (1.836909530733566e-16-3.0i)
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 angle part of its polar form.
Complex.polar(3, Math::PI/2).arg #=> 1.5707963267948966
Returns an array; [cmp.abs, cmp.arg].
Complex(1, 2).polar #=> [2.23606797749979, 1.1071487177940904]
Returns the numerator.
1 2 3+4i <- numerator
- + -i -> ----
2 3 6 <- denominator
c = Complex('1/2+2/3i') #=> ((1/2)+(2/3)*i)
n = c.numerator #=> (3+4i)
d = c.denominator #=> 6
n / d #=> ((1/2)+(2/3)*i)
Complex(Rational(n.real, d), Rational(n.imag, d))
#=> ((1/2)+(2/3)*i)
See denominator.