Update RubyGems software to the latest version.
Updates the TarHeader’s checksum
Returns true
if this gem is installable for the current platform.
Returns true
if this gem is installable for the current platform.
Returns true if this specification is installable on this platform.
Returns the element at index
. A negative index counts from the end of self
. Returns nil
if the index is out of range. See also Array#[]
.
a = [ "a", "b", "c", "d", "e" ] a.at(0) #=> "a" a.at(-1) #=> "e"
Appends the elements of other_ary
to self
.
[ "a", "b" ].concat( ["c", "d"] ) #=> [ "a", "b", "c", "d" ] a = [ 1, 2, 3 ] a.concat( [ 4, 5 ] ) a #=> [ 1, 2, 3, 4, 5 ]
See also Array#+
.
Returns a new array that is a one-dimensional flattening of self
(recursively).
That is, for every element that is an array, extract its elements into the new array.
The optional level
argument determines the level of recursion to flatten.
s = [ 1, 2, 3 ] #=> [1, 2, 3] t = [ 4, 5, 6, [7, 8] ] #=> [4, 5, 6, [7, 8]] a = [ s, t, 9, 10 ] #=> [[1, 2, 3], [4, 5, 6, [7, 8]], 9, 10] a.flatten #=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] a = [ 1, 2, [3, [4, 5] ] ] a.flatten(1) #=> [1, 2, 3, [4, 5]]
Flattens self
in place.
Returns nil
if no modifications were made (i.e., the array contains no subarrays.)
The optional level
argument determines the level of recursion to flatten.
a = [ 1, 2, [3, [4, 5] ] ] a.flatten! #=> [1, 2, 3, 4, 5] a.flatten! #=> nil a #=> [1, 2, 3, 4, 5] a = [ 1, 2, [3, [4, 5] ] ] a.flatten!(1) #=> [1, 2, 3, [4, 5]]
When invoked with a block, yields all combinations of length n
of elements from the array and then returns the array itself.
The implementation makes no guarantees about the order in which the combinations are yielded.
If no block is given, an Enumerator
is returned instead.
Examples:
a = [1, 2, 3, 4] a.combination(1).to_a #=> [[1],[2],[3],[4]] a.combination(2).to_a #=> [[1,2],[1,3],[1,4],[2,3],[2,4],[3,4]] a.combination(3).to_a #=> [[1,2,3],[1,2,4],[1,3,4],[2,3,4]] a.combination(4).to_a #=> [[1,2,3,4]] a.combination(0).to_a #=> [[]] # one combination of length 0 a.combination(5).to_a #=> [] # no combinations of length 5
Returns first n
elements from the array.
If a negative number is given, raises an ArgumentError
.
See also Array#drop
a = [1, 2, 3, 4, 5, 0] a.take(3) #=> [1, 2, 3]
Returns a complex object which denotes the given rectangular form.
Complex.rectangular(1, 2) #=> (1+2i)
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.
Returns the denominator (lcm of both denominator - real and imag).
See numerator.
Returns the value as a rational if possible (the imaginary part should be exactly zero).
Complex(1.0/3, 0).rationalize #=> (1/3) Complex(1, 0.0).rationalize # RangeError Complex(1, 2).rationalize # RangeError
See to_r.
Returns zero as a rational. The optional argument eps is always ignored.