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 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 the integer square root of the non-negative integer n, which is the largest non-negative integer less than or equal to the square root of numeric.
Integer.sqrt(0) # => 0 Integer.sqrt(1) # => 1 Integer.sqrt(24) # => 4 Integer.sqrt(25) # => 5 Integer.sqrt(10**400) # => 10**200
If numeric is not an Integer, it is converted to an Integer:
Integer.sqrt(Complex(4, 0)) # => 2 Integer.sqrt(Rational(4, 1)) # => 2 Integer.sqrt(4.0) # => 2 Integer.sqrt(3.14159) # => 1
This method is equivalent to Math.sqrt(numeric).floor, except that the result of the latter code may differ from the true value due to the limited precision of floating point arithmetic.
Integer.sqrt(10**46) # => 100000000000000000000000 Math.sqrt(10**46).floor # => 99999999999999991611392
Raises an exception if numeric is negative.
Returns true if all bits that are set (=1) in mask are also set in self; returns false otherwise.
Example values:
0b1010101 self
0b1010100 mask
0b1010100 self & mask
true self.allbits?(mask)
0b1010100 self
0b1010101 mask
0b1010100 self & mask
false self.allbits?(mask)
Related: Integer#anybits?, Integer#nobits?.
Returns true if any bit that is set (=1) in mask is also set in self; returns false otherwise.
Example values:
0b10000010 self
0b11111111 mask
0b10000010 self & mask
true self.anybits?(mask)
0b00000000 self
0b11111111 mask
0b00000000 self & mask
false self.anybits?(mask)
Related: Integer#allbits?, Integer#nobits?.
Returns true if no bit that is set (=1) in mask is also set in self; returns false otherwise.
Example values:
0b11110000 self
0b00001111 mask
0b00000000 self & mask
true self.nobits?(mask)
0b00000001 self
0b11111111 mask
0b00000001 self & mask
false self.nobits?(mask)
Related: Integer#allbits?, Integer#anybits?.
Returns an array of integers representing the base-radix digits of self; the first element of the array represents the least significant digit:
12345.digits # => [5, 4, 3, 2, 1] 12345.digits(7) # => [4, 6, 6, 0, 5] 12345.digits(100) # => [45, 23, 1]
Raises an exception if self is negative or base is less than 2.
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 absolute part of its polar form.
Complex(-1).abs #=> 1 Complex(3.0, -4.0).abs #=> 5.0
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 true if cmp‘s real and imaginary parts are both finite numbers, otherwise returns false.
Returns 1 if cmp‘s real or imaginary part is an infinite number, otherwise returns nil.
For example: (1+1i).infinite? #=> nil (Float::INFINITY + 1i).infinite? #=> 1