Returns true if num is a finite number, otherwise returns false.
Inserts the given other_string into self; returns self.
If the Integer index is positive, inserts other_string at offset index:
'foo'.insert(1, 'bar') # => "fbaroo"
If the Integer index is negative, counts backward from the end of self and inserts other_string at offset index+1 (that is, after self[index]):
'foo'.insert(-2, 'bar') # => "fobaro"
Returns a MatchData object (or nil) based on self and the given pattern.
Note: also updates Special global variables at Regexp.
Computes regexp by converting pattern (if not already a Regexp).
regexp = Regexp.new(pattern)
Computes matchdata, which will be either a MatchData object or nil (see Regexp#match):
matchdata = <tt>regexp.match(self)
With no block given, returns the computed matchdata:
'foo'.match('f') # => #<MatchData "f"> 'foo'.match('o') # => #<MatchData "o"> 'foo'.match('x') # => nil
If Integer argument offset is given, the search begins at index offset:
'foo'.match('f', 1) # => nil 'foo'.match('o', 1) # => #<MatchData "o">
With a block given, calls the block with the computed matchdata and returns the block’s return value:
'foo'.match(/o/) {|matchdata| matchdata } # => #<MatchData "o"> 'foo'.match(/x/) {|matchdata| matchdata } # => nil 'foo'.match(/f/, 1) {|matchdata| matchdata } # => nil
Returns true or false based on whether a match is found for self and pattern.
Note: does not update Special global variables at Regexp.
Computes regexp by converting pattern (if not already a Regexp).
regexp = Regexp.new(pattern)
Returns true if self+.match(regexp) returns a MatchData object, false otherwise:
'foo'.match?(/o/) # => true 'foo'.match?('o') # => true 'foo'.match?(/x/) # => false
If Integer argument offset is given, the search begins at index offset:
'foo'.match?('f', 1) # => false 'foo'.match?('o', 1) # => true
Returns the integer index of the first match for the given argument, or nil if none found; the search of self is forward, and begins at position offset (in characters).
With string argument substring, returns the index of the first matching substring in self:
'foo'.index('f') # => 0 'foo'.index('o') # => 1 'foo'.index('oo') # => 1 'foo'.index('ooo') # => nil 'тест'.index('с') # => 2 'こんにちは'.index('ち') # => 3
With Regexp argument regexp, returns the index of the first match in self:
'foo'.index(/o./) # => 1 'foo'.index(/.o/) # => 0
With positive integer offset, begins the search at position offset:
'foo'.index('o', 1) # => 1 'foo'.index('o', 2) # => 2 'foo'.index('o', 3) # => nil 'тест'.index('с', 1) # => 2 'こんにちは'.index('ち', 2) # => 3
With negative integer offset, selects the search position by counting backward from the end of self:
'foo'.index('o', -1) # => 2 'foo'.index('o', -2) # => 1 'foo'.index('o', -3) # => 1 'foo'.index('o', -4) # => nil 'foo'.index(/o./, -2) # => 1 'foo'.index(/.o/, -2) # => 1
Related: String#rindex.
Returns the Integer byte-based index of the first occurrence of the given substring, or nil if none found:
'foo'.byteindex('f') # => 0 'foo'.byteindex('o') # => 1 'foo'.byteindex('oo') # => 1 'foo'.byteindex('ooo') # => nil
Returns the Integer byte-based index of the first match for the given Regexp regexp, or nil if none found:
'foo'.byteindex(/f/) # => 0 'foo'.byteindex(/o/) # => 1 'foo'.byteindex(/oo/) # => 1 'foo'.byteindex(/ooo/) # => nil
Integer argument offset, if given, specifies the byte-based position in the string to begin the search:
'foo'.byteindex('o', 1) # => 1 'foo'.byteindex('o', 2) # => 2 'foo'.byteindex('o', 3) # => nil
If offset is negative, counts backward from the end of self:
'foo'.byteindex('o', -1) # => 2 'foo'.byteindex('o', -2) # => 1 'foo'.byteindex('o', -3) # => 1 'foo'.byteindex('o', -4) # => nil
If offset does not land on character (codepoint) boundary, IndexError is raised.
Related: String#index, String#byterindex.
Returns the Integer index of the last occurrence of the given substring, or nil if none found:
'foo'.rindex('f') # => 0 'foo'.rindex('o') # => 2 'foo'.rindex('oo') # => 1 'foo'.rindex('ooo') # => nil
Returns the Integer index of the last match for the given Regexp regexp, or nil if none found:
'foo'.rindex(/f/) # => 0 'foo'.rindex(/o/) # => 2 'foo'.rindex(/oo/) # => 1 'foo'.rindex(/ooo/) # => nil
The last match means starting at the possible last position, not the last of longest matches.
'foo'.rindex(/o+/) # => 2 $~ #=> #<MatchData "o">
To get the last longest match, needs to combine with negative lookbehind.
'foo'.rindex(/(?<!o)o+/) # => 1 $~ #=> #<MatchData "oo">
Or String#index with negative lookforward.
'foo'.index(/o+(?!.*o)/) # => 1 $~ #=> #<MatchData "oo">
Integer argument offset, if given and non-negative, specifies the maximum starting position in the
string to _end_ the search: 'foo'.rindex('o', 0) # => nil 'foo'.rindex('o', 1) # => 1 'foo'.rindex('o', 2) # => 2 'foo'.rindex('o', 3) # => 2
If offset is a negative Integer, the maximum starting position in the string to end the search is the sum of the string’s length and offset:
'foo'.rindex('o', -1) # => 2 'foo'.rindex('o', -2) # => 1 'foo'.rindex('o', -3) # => nil 'foo'.rindex('o', -4) # => nil
Related: String#index.
Returns the Integer byte-based index of the last occurrence of the given substring, or nil if none found:
'foo'.byterindex('f') # => 0 'foo'.byterindex('o') # => 2 'foo'.byterindex('oo') # => 1 'foo'.byterindex('ooo') # => nil
Returns the Integer byte-based index of the last match for the given Regexp regexp, or nil if none found:
'foo'.byterindex(/f/) # => 0 'foo'.byterindex(/o/) # => 2 'foo'.byterindex(/oo/) # => 1 'foo'.byterindex(/ooo/) # => nil
The last match means starting at the possible last position, not the last of longest matches.
'foo'.byterindex(/o+/) # => 2 $~ #=> #<MatchData "o">
To get the last longest match, needs to combine with negative lookbehind.
'foo'.byterindex(/(?<!o)o+/) # => 1 $~ #=> #<MatchData "oo">
Or String#byteindex with negative lookforward.
'foo'.byteindex(/o+(?!.*o)/) # => 1 $~ #=> #<MatchData "oo">
Integer argument offset, if given and non-negative, specifies the maximum starting byte-based position in the
string to _end_ the search: 'foo'.byterindex('o', 0) # => nil 'foo'.byterindex('o', 1) # => 1 'foo'.byterindex('o', 2) # => 2 'foo'.byterindex('o', 3) # => 2
If offset is a negative Integer, the maximum starting position in the string to end the search is the sum of the string’s length and offset:
'foo'.byterindex('o', -1) # => 2 'foo'.byterindex('o', -2) # => 1 'foo'.byterindex('o', -3) # => nil 'foo'.byterindex('o', -4) # => nil
If offset does not land on character (codepoint) boundary, IndexError is raised.
Related: String#byteindex.
Returns a printable version of self, enclosed in double-quotes, and with special characters escaped:
s = "foo\tbar\tbaz\n" s.inspect # => "\"foo\\tbar\\tbaz\\n\""
Forms substrings (“lines”) of self according to the given arguments (see String#each_line for details); returns the lines in an array.
Returns an array of the codepoints in self; each codepoint is the integer value for a character:
'hello'.codepoints # => [104, 101, 108, 108, 111] 'тест'.codepoints # => [1090, 1077, 1089, 1090] 'こんにちは'.codepoints # => [12371, 12435, 12395, 12385, 12399]
Returns the Symbol corresponding to str, creating the symbol if it did not previously exist. See Symbol#id2name.
"Koala".intern #=> :Koala s = 'cat'.to_sym #=> :cat s == :cat #=> true s = '@cat'.to_sym #=> :@cat s == :@cat #=> true
This can also be used to create symbols that cannot be represented using the :xxx notation.
'cat and dog'.to_sym #=> :"cat and dog"
Returns true if self contains other_string, false otherwise:
s = 'foo' s.include?('f') # => true s.include?('fo') # => true s.include?('food') # => false
Returns the Encoding object that represents the encoding of obj.
Returns true if self is not Infinity, -Infinity, or NaN, false otherwise:
f = 2.0 # => 2.0 f.finite? # => true f = 1.0/0.0 # => Infinity f.finite? # => false f = -1.0/0.0 # => -Infinity f.finite? # => false f = 0.0/0.0 # => NaN f.finite? # => false
Returns a string containing a representation of self; depending of the value of self, the string representation may contain:
A fixed-point number.
A number in “scientific notation” (containing an exponent).
‘Infinity’.
‘-Infinity’.
‘NaN’ (indicating not-a-number).
3.14.to_s # => “3.14” (10.1**50).to_s # => “1.644631821843879e+50” (10.1**500).to_s # => “Infinity” (-10.1**500).to_s # => “-Infinity” (0.0/0.0).to_s # => “NaN”
Forces the fiber to be blocking for the duration of the block. Returns the result of the block.
See the “Non-blocking fibers” section in class docs for details.
Returns true if fiber is blocking and false otherwise. Fiber is non-blocking if it was created via passing blocking: false to Fiber.new, or via Fiber.schedule.
Note that, even if the method returns false, the fiber behaves differently only if Fiber.scheduler is set in the current thread.
See the “Non-blocking fibers” section in class docs for details.
Returns false if the current fiber is non-blocking. Fiber is non-blocking if it was created via passing blocking: false to Fiber.new, or via Fiber.schedule.
If the current Fiber is blocking, the method returns 1. Future developments may allow for situations where larger integers could be returned.
Note that, even if the method returns false, Fiber behaves differently only if Fiber.scheduler is set in the current thread.
See the “Non-blocking fibers” section in class docs for details.
Return a string describing this Dir object.
Repositions dir to the first entry.
d = Dir.new("testdir") d.read #=> "." d.rewind #=> #<Dir:0x401b3fb0> d.read #=> "."
Deletes the named directory. Raises a subclass of SystemCallError if the directory isn’t empty.