Replaces the content of self with the content of other_array; returns self:
a = [:foo, 'bar', 2] a.replace(['foo', :bar, 3]) # => ["foo", :bar, 3]
Replaces the contents of self with the contents of other_string:
s = 'foo' # => "foo" s.replace('bar') # => "bar"
With a block given, forms the substrings (“lines”) that are the result of splitting self at each occurrence of the given line separator line_sep; passes each line to the block; returns self:
s = <<~EOT This is the first line. This is line two. This is line four. This is line five. EOT s.each_line {|line| p line }
Output:
"This is the first line.\n" "This is line two.\n" "\n" "This is line four.\n" "This is line five.\n"
With a different line_sep:
s.each_line(' is ') {|line| p line }
Output:
"This is " "the first line.\nThis is " "line two.\n\nThis is " "line four.\nThis is " "line five.\n"
With chomp as true, removes the trailing line_sep from each line:
s.each_line(chomp: true) {|line| p line }
Output:
"This is the first line." "This is line two." "" "This is line four." "This is line five."
With an empty string as line_sep, forms and passes “paragraphs” by splitting at each occurrence of two or more newlines:
s.each_line('') {|line| p line }
Output:
"This is the first line.\nThis is line two.\n\n" "This is line four.\nThis is line five.\n"
With no block given, returns an enumerator.
Changes the encoding of self to encoding, which may be a string encoding name or an Encoding object; returns self:
s = 'łał' s.bytes # => [197, 130, 97, 197, 130] s.encoding # => #<Encoding:UTF-8> s.force_encoding('ascii') # => "\xC5\x82a\xC5\x82" s.encoding # => #<Encoding:US-ASCII>
Does not change the underlying bytes:
s.bytes # => [197, 130, 97, 197, 130]
Makes the change even if the given encoding is invalid for self (as is the change above):
s.valid_encoding? # => false s.force_encoding(Encoding::UTF_8) # => "łał" s.valid_encoding? # => true
Returns true if self is encoded correctly, false otherwise:
"\xc2\xa1".force_encoding("UTF-8").valid_encoding? # => true "\xc2".force_encoding("UTF-8").valid_encoding? # => false "\x80".force_encoding("UTF-8").valid_encoding? # => false
Like backtrace, but returns each line of the execution stack as a Thread::Backtrace::Location. Accepts the same arguments as backtrace.
f = Fiber.new { Fiber.yield } f.resume loc = f.backtrace_locations.first loc.label #=> "yield" loc.path #=> "test.rb" loc.lineno #=> 1
Returns the list of available encoding names.
Encoding.name_list
#=> ["US-ASCII", "ASCII-8BIT", "UTF-8",
"ISO-8859-1", "Shift_JIS", "EUC-JP",
"Windows-31J",
"BINARY", "CP932", "eucJP"]
Returns an array of instance variable names for the receiver. Note that simply defining an accessor does not create the corresponding instance variable.
class Fred attr_accessor :a1 def initialize @iv = 3 end end Fred.new.instance_variables #=> [:@iv]
Returns true if obj is an instance of the given class. See also Object#kind_of?.
class A; end class B < A; end class C < B; end b = B.new b.instance_of? A #=> false b.instance_of? B #=> true b.instance_of? C #=> false
Returns any backtrace associated with the exception. This method is similar to Exception#backtrace, but the backtrace is an array of Thread::Backtrace::Location.
This method is not affected by Exception#set_backtrace().
Sets the backtrace information associated with exc. The backtrace must be an array of String objects or a single String in the format described in Exception#backtrace.
Defines a named attribute for this module, where the name is symbol.id2name, creating an instance variable (@name) and a corresponding access method to read it. Also creates a method called name= to set the attribute. String arguments are converted to symbols. Returns an array of defined method names as symbols.
module Mod attr_accessor(:one, :two) #=> [:one, :one=, :two, :two=] end Mod.instance_methods.sort #=> [:one, :one=, :two, :two=]
Returns an array containing the names of the public and protected instance methods in the receiver. For a module, these are the public and protected methods; for a class, they are the instance (not singleton) methods. If the optional parameter is false, the methods of any ancestors are not included.
module A def method1() end end class B include A def method2() end end class C < B def method3() end end A.instance_methods(false) #=> [:method1] B.instance_methods(false) #=> [:method2] B.instance_methods(true).include?(:method1) #=> true C.instance_methods(false) #=> [:method3] C.instance_methods.include?(:method2) #=> true
Note that method visibility changes in the current class, as well as aliases, are considered as methods of the current class by this method:
class C < B alias method4 method2 protected :method2 end C.instance_methods(false).sort #=> [:method2, :method3, :method4]
Returns an UnboundMethod representing the given instance method in mod.
class Interpreter def do_a() print "there, "; end def do_d() print "Hello "; end def do_e() print "!\n"; end def do_v() print "Dave"; end Dispatcher = { "a" => instance_method(:do_a), "d" => instance_method(:do_d), "e" => instance_method(:do_e), "v" => instance_method(:do_v) } def interpret(string) string.each_char {|b| Dispatcher[b].bind(self).call } end end interpreter = Interpreter.new interpreter.interpret('dave')
produces:
Hello there, Dave!
Makes new_name a new copy of the method old_name. This can be used to retain access to methods that are overridden.
module Mod alias_method :orig_exit, :exit #=> :orig_exit def exit(code=0) puts "Exiting with code #{code}" orig_exit(code) end end include Mod exit(99)
produces:
Exiting with code 99
Execute the provided block, but preserve the precision limit
BigDecimal.limit(100) puts BigDecimal.limit BigDecimal.save_limit do BigDecimal.limit(200) puts BigDecimal.limit end puts BigDecimal.limit
Returns the number of decimal significant digits in self.
BigDecimal("0").n_significant_digits # => 0 BigDecimal("1").n_significant_digits # => 1 BigDecimal("1.1").n_significant_digits # => 2 BigDecimal("3.1415").n_significant_digits # => 5 BigDecimal("-1e20").n_significant_digits # => 1 BigDecimal("1e-20").n_significant_digits # => 1 BigDecimal("Infinity").n_significant_digits # => 0 BigDecimal("-Infinity").n_significant_digits # => 0 BigDecimal("NaN").n_significant_digits # => 0
Return the accept character set for all new CGI instances.
Implemented for compatibility; returns true unless jd is invalid (i.e., not a Numeric).
Date.valid_jd?(2451944) # => true
See argument start.
Related: Date.jd.
Returns true if the arguments define a valid ordinal date, false otherwise:
Date.valid_ordinal?(2001, 34) # => true Date.valid_ordinal?(2001, 366) # => false
See argument start.
Related: Date.jd, Date.ordinal.
Returns true if the arguments define a valid ordinal date, false otherwise:
Date.valid_date?(2001, 2, 3) # => true Date.valid_date?(2001, 2, 29) # => false Date.valid_date?(2001, 2, -1) # => true
See argument start.
Returns true if the arguments define a valid ordinal date, false otherwise:
Date.valid_date?(2001, 2, 3) # => true Date.valid_date?(2001, 2, 29) # => false Date.valid_date?(2001, 2, -1) # => true
See argument start.
Returns true if the arguments define a valid commercial date, false otherwise:
Date.valid_commercial?(2001, 5, 6) # => true Date.valid_commercial?(2001, 5, 8) # => false
See Date.commercial.
See argument start.
Related: Date.jd, Date.commercial.