Returns true
if field 'Transfer-Encoding'
exists and has value 'chunked'
, false
otherwise; see Transfer-Encoding response header:
res = Net::HTTP.get_response(hostname, '/todos/1') res['Transfer-Encoding'] # => "chunked" res.chunked? # => true
Zlib::GzipReader
wrapper that unzips data
.
Raises a TypeError
to prevent cloning.
Removes the element of self
at the given index
, which must be an integer-convertible object.
When index
is non-negative, deletes the element at offset index
:
a = [:foo, 'bar', 2] a.delete_at(1) # => "bar" a # => [:foo, 2]
When index
is negative, counts backward from the end of the array:
a = [:foo, 'bar', 2] a.delete_at(-2) # => "bar" a # => [:foo, 2]
When index
is out of range, returns nil
.
a = [:foo, 'bar', 2] a.delete_at(3) # => nil a.delete_at(-4) # => nil
Related: see Methods for Deleting.
With a block given, calls the block with each element of self
; removes the element if the block returns a truthy value; returns self
:
a = [:foo, 'bar', 2, 'bat'] a.delete_if {|element| element.to_s.start_with?('b') } # => [:foo, 2]
With no block given, returns a new Enumerator
.
Related: see Methods for Deleting.
With a block given, calls the block with each successive element of self
; stops iterating if the block returns false
or nil
; returns a new array containing those elements for which the block returned a truthy value:
a = [0, 1, 2, 3, 4, 5] a.take_while {|element| element < 3 } # => [0, 1, 2] a.take_while {|element| true } # => [0, 1, 2, 3, 4, 5] a.take_while {|element| false } # => []
With no block given, returns a new Enumerator
.
Does not modify self
.
Related: see Methods for Fetching.
With a block given, calls the block with each successive element of self
; stops if the block returns false
or nil
; returns a new array omitting those elements for which the block returned a truthy value; does not modify self
:
a = [0, 1, 2, 3, 4, 5] a.drop_while {|element| element < 3 } # => [3, 4, 5]
With no block given, returns a new Enumerator
.
Related: see Methods for Fetching.
Returns the number of bits of the value of self
, which is the bit position of the highest-order bit that is different from the sign bit (where the least significant bit has bit position 1). If there is no such bit (zero or minus one), returns zero.
This method returns ceil(log2(self < 0 ? -self : self + 1))
>.
(-2**1000-1).bit_length # => 1001 (-2**1000).bit_length # => 1000 (-2**1000+1).bit_length # => 1000 (-2**12-1).bit_length # => 13 (-2**12).bit_length # => 12 (-2**12+1).bit_length # => 12 -0x101.bit_length # => 9 -0x100.bit_length # => 8 -0xff.bit_length # => 8 -2.bit_length # => 1 -1.bit_length # => 0 0.bit_length # => 0 1.bit_length # => 1 0xff.bit_length # => 8 0x100.bit_length # => 9 (2**12-1).bit_length # => 12 (2**12).bit_length # => 13 (2**12+1).bit_length # => 13 (2**1000-1).bit_length # => 1000 (2**1000).bit_length # => 1001 (2**1000+1).bit_length # => 1001
For Integer n, this method can be used to detect overflow in Array#pack
:
if n.bit_length < 32 [n].pack('l') # No overflow. else raise 'Overflow' end
Imports methods from modules. Unlike Module#include
, Refinement#import_methods
copies methods and adds them into the refinement, so the refinement is activated in the imported methods.
Note that due to method copying, only methods defined in Ruby
code can be imported.
module StrUtils def indent(level) ' ' * level + self end end module M refine String do import_methods StrUtils end end using M "foo".indent(3) #=> " foo" module M refine String do import_methods Enumerable # Can't import method which is not defined with Ruby code: Enumerable#drop end end
Returns a copy of self
with leading substring prefix
removed:
'hello'.delete_prefix('hel') # => "lo" 'hello'.delete_prefix('llo') # => "hello" 'тест'.delete_prefix('те') # => "ст" 'こんにちは'.delete_prefix('こん') # => "にちは"
Related: String#delete_prefix!
, String#delete_suffix
.
Returns a copy of self
with trailing substring suffix
removed:
'hello'.delete_suffix('llo') # => "he" 'hello'.delete_suffix('hel') # => "hello" 'тест'.delete_suffix('ст') # => "те" 'こんにちは'.delete_suffix('ちは') # => "こんに"
Related: String#delete_suffix!
, String#delete_prefix
.
Like String#delete_prefix
, except that self
is modified in place. Returns self
if the prefix is removed, nil
otherwise.
Like String#delete_suffix
, except that self
is modified in place. Returns self
if the suffix is removed, nil
otherwise.
Calls the given block with each successive codepoint from self
; each codepoint is the integer value for a character; returns self
:
'hello'.each_codepoint {|codepoint| print codepoint, ' ' } print "\n" 'тест'.each_codepoint {|codepoint| print codepoint, ' ' } print "\n" 'こんにちは'.each_codepoint {|codepoint| print codepoint, ' ' } print "\n"
Output:
104 101 108 108 111 1090 1077 1089 1090 12371 12435 12395 12385 12399
Returns an enumerator if no block is given.
Returns true
if the named file is readable by the real user and group id of this process. See access(3).
Note that some OS-level security features may cause this to return true even though the file is not readable by the real user/group.
If file_name is readable by others, returns an integer representing the file permission bits of file_name. Returns nil
otherwise. The meaning of the bits is platform dependent; on Unix systems, see stat(2)
.
file_name can be an IO
object.
File.world_readable?("/etc/passwd") #=> 420 m = File.world_readable?("/etc/passwd") sprintf("%o", m) #=> "644"
Returns true
if the named file is writable by the real user and group id of this process. See access(3).
Note that some OS-level security features may cause this to return true even though the file is not writable by the real user/group.
If file_name is writable by others, returns an integer representing the file permission bits of file_name. Returns nil
otherwise. The meaning of the bits is platform dependent; on Unix systems, see stat(2)
.
file_name can be an IO
object.
File.world_writable?("/tmp") #=> 511 m = File.world_writable?("/tmp") sprintf("%o", m) #=> "777"
Returns true
if the named file is executable by the real user and group id of this process. See access(3).
Windows does not support execute permissions separately from read permissions. On Windows, a file is only considered executable if it ends in .bat, .cmd, .com, or .exe.
Note that some OS-level security features may cause this to return true even though the file is not executable by the real user/group.