Returns a string representation of self:
Complex.rect(2).inspect # => "(2+0i)" Complex.rect(-8, 6).inspect # => "(-8+6i)" Complex.rect(0, Rational(1, 2)).inspect # => "(0+(1/2)*i)" Complex.rect(0, Float::INFINITY).inspect # => "(0+Infinity*i)" Complex.rect(Float::NAN, Float::NAN).inspect # => "(NaN+NaN*i)"
Returns a Rational object whose value is exactly or approximately equivalent to that of self.real.
With no argument epsilon given, returns a Rational object whose value is exactly equal to that of self.real.rationalize:
Complex.rect(1, 0).rationalize # => (1/1) Complex.rect(1, Rational(0, 1)).rationalize # => (1/1) Complex.rect(3.14159, 0).rationalize # => (314159/100000)
With argument epsilon given, returns a Rational object whose value is exactly or approximately equal to that of self.real to the given precision:
Complex.rect(3.14159, 0).rationalize(0.1) # => (16/5) Complex.rect(3.14159, 0).rationalize(0.01) # => (22/7) Complex.rect(3.14159, 0).rationalize(0.001) # => (201/64) Complex.rect(3.14159, 0).rationalize(0.0001) # => (333/106) Complex.rect(3.14159, 0).rationalize(0.00001) # => (355/113) Complex.rect(3.14159, 0).rationalize(0.000001) # => (7433/2366) Complex.rect(3.14159, 0).rationalize(0.0000001) # => (9208/2931) Complex.rect(3.14159, 0).rationalize(0.00000001) # => (47460/15107) Complex.rect(3.14159, 0).rationalize(0.000000001) # => (76149/24239) Complex.rect(3.14159, 0).rationalize(0.0000000001) # => (314159/100000) Complex.rect(3.14159, 0).rationalize(0.0) # => (3537115888337719/1125899906842624)
Related: Complex#to_r.
Returns zero as a Rational:
nil.rationalize # => (0/1)
Argument eps is ignored.
Returns a 2-element array containing two numeric elements, formed from the two operands self and other, of a common compatible type.
Of the Core and Standard Library classes, Integer, Rational, and Complex use this implementation.
Examples:
i = 2 # => 2 i.coerce(3) # => [3, 2] i.coerce(3.0) # => [3.0, 2.0] i.coerce(Rational(1, 2)) # => [0.5, 2.0] i.coerce(Complex(3, 4)) # Raises RangeError. r = Rational(5, 2) # => (5/2) r.coerce(2) # => [(2/1), (5/2)] r.coerce(2.0) # => [2.0, 2.5] r.coerce(Rational(2, 3)) # => [(2/3), (5/2)] r.coerce(Complex(3, 4)) # => [(3+4i), ((5/2)+0i)] c = Complex(2, 3) # => (2+3i) c.coerce(2) # => [(2+0i), (2+3i)] c.coerce(2.0) # => [(2.0+0i), (2+3i)] c.coerce(Rational(1, 2)) # => [((1/2)+0i), (2+3i)] c.coerce(Complex(3, 4)) # => [(3+4i), (2+3i)]
Raises an exception if any type conversion fails.
Returns self.
Raises an exception if the value for freeze is neither true nor nil.
Related: Numeric#dup.
Returns +self+ if +self+ is not a zero value, +nil+ otherwise;
uses method <tt>zero?</tt> for the evaluation.
The returned +self+ allows the method to be chained:
a = %w[z Bb bB bb BB a aA Aa AA A]
a.sort {|a, b| (a.downcase <=> b.downcase).nonzero? || a <=> b }
# => ["A", "a", "AA", "Aa", "aA", "BB", "Bb", "bB", "bb", "z"]
Of the Core and Standard Library classes,
Integer, Float, Rational, and Complex use this implementation.
Related: zero?
Generates a sequence of numbers; with a block given, traverses the sequence.
Of the Core and Standard Library classes, Integer, Float, and Rational use this implementation.
A quick example:
squares = [] 1.step(by: 2, to: 10) {|i| squares.push(i*i) } squares # => [1, 9, 25, 49, 81]
The generated sequence:
Begins with self.
Continues at intervals of by (which may not be zero).
Ends with the last number that is within or equal to to; that is, less than or equal to to if by is positive, greater than or equal to to if by is negative. If to is nil, the sequence is of infinite length.
If a block is given, calls the block with each number in the sequence; returns self. If no block is given, returns an Enumerator::ArithmeticSequence.
Keyword Arguments
With keyword arguments by and to, their values (or defaults) determine the step and limit:
# Both keywords given. squares = [] 4.step(by: 2, to: 10) {|i| squares.push(i*i) } # => 4 squares # => [16, 36, 64, 100] cubes = [] 3.step(by: -1.5, to: -3) {|i| cubes.push(i*i*i) } # => 3 cubes # => [27.0, 3.375, 0.0, -3.375, -27.0] squares = [] 1.2.step(by: 0.2, to: 2.0) {|f| squares.push(f*f) } squares # => [1.44, 1.9599999999999997, 2.5600000000000005, 3.24, 4.0] squares = [] Rational(6/5).step(by: 0.2, to: 2.0) {|r| squares.push(r*r) } squares # => [1.0, 1.44, 1.9599999999999997, 2.5600000000000005, 3.24, 4.0] # Only keyword to given. squares = [] 4.step(to: 10) {|i| squares.push(i*i) } # => 4 squares # => [16, 25, 36, 49, 64, 81, 100] # Only by given. # Only keyword by given squares = [] 4.step(by:2) {|i| squares.push(i*i); break if i > 10 } squares # => [16, 36, 64, 100, 144] # No block given. e = 3.step(by: -1.5, to: -3) # => (3.step(by: -1.5, to: -3)) e.class # => Enumerator::ArithmeticSequence
Positional Arguments
With optional positional arguments to and by, their values (or defaults) determine the step and limit:
squares = [] 4.step(10, 2) {|i| squares.push(i*i) } # => 4 squares # => [16, 36, 64, 100] squares = [] 4.step(10) {|i| squares.push(i*i) } squares # => [16, 25, 36, 49, 64, 81, 100] squares = [] 4.step {|i| squares.push(i*i); break if i > 10 } # => nil squares # => [16, 25, 36, 49, 64, 81, 100, 121]
Implementation Notes
If all the arguments are integers, the loop operates using an integer counter.
If any of the arguments are floating point numbers, all are converted to floats, and the loop is executed floor(n + n*Float::EPSILON) + 1 times, where n = (limit - self)/step.
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 printable version of self, enclosed in double-quotes, and with special characters escaped:
s = "foo\tbar\tbaz\n" s.inspect # => "\"foo\\tbar\\tbaz\\n\""
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 a left-justified copy of self.
If integer argument size is greater than the size (in characters) of self, returns a new string of length size that is a copy of self, left justified and padded on the right with pad_string:
'hello'.ljust(10) # => "hello " ' hello'.ljust(10) # => " hello " 'hello'.ljust(10, 'ab') # => "helloababa" 'тест'.ljust(10) # => "тест " 'こんにちは'.ljust(10) # => "こんにちは "
If size is not greater than the size of self, returns a copy of self:
'hello'.ljust(5) # => "hello" 'hello'.ljust(1) # => "hello"
Related: String#rjust, String#center.
Returns a right-justified copy of self.
If integer argument size is greater than the size (in characters) of self, returns a new string of length size that is a copy of self, right justified and padded on the left with pad_string:
'hello'.rjust(10) # => " hello" 'hello '.rjust(10) # => " hello " 'hello'.rjust(10, 'ab') # => "ababahello" 'тест'.rjust(10) # => " тест" 'こんにちは'.rjust(10) # => " こんにちは"
If size is not greater than the size of self, returns a copy of self:
'hello'.rjust(5, 'ab') # => "hello" 'hello'.rjust(1, 'ab') # => "hello"
Related: String#ljust, String#center.
Returns a copy of the receiver with leading and trailing whitespace removed; see Whitespace in Strings:
whitespace = "\x00\t\n\v\f\r " s = whitespace + 'abc' + whitespace s # => "\u0000\t\n\v\f\r abc\u0000\t\n\v\f\r " s.strip # => "abc"
Related: String#lstrip, String#rstrip.
Returns a copy of self with leading whitespace removed; see Whitespace in Strings:
whitespace = "\x00\t\n\v\f\r " s = whitespace + 'abc' + whitespace s # => "\u0000\t\n\v\f\r abc\u0000\t\n\v\f\r " s.lstrip # => "abc\u0000\t\n\v\f\r "
Related: String#rstrip, String#strip.
Returns a copy of the receiver with trailing whitespace removed; see Whitespace in Strings:
whitespace = "\x00\t\n\v\f\r " s = whitespace + 'abc' + whitespace s # => "\u0000\t\n\v\f\r abc\u0000\t\n\v\f\r " s.rstrip # => "\u0000\t\n\v\f\r abc"
Related: String#lstrip, String#strip.
Like String#strip, except that any modifications are made in self; returns self if any modification are made, nil otherwise.
Related: String#lstrip!, String#strip!.
Like String#lstrip, except that any modifications are made in self; returns self if any modification are made, nil otherwise.
Related: String#rstrip!, String#strip!.
Like String#rstrip, except that any modifications are made in self; returns self if any modification are made, nil otherwise.
Related: String#lstrip!, String#strip!.
Returns the total number of characters in self that are specified by the given selectors (see Multiple Character Selectors):
a = "hello world" a.count "lo" #=> 5 a.count "lo", "o" #=> 2 a.count "hello", "^l" #=> 4 a.count "ej-m" #=> 4 "hello^world".count "\\^aeiou" #=> 4 "hello-world".count "a\\-eo" #=> 4 c = "hello world\\r\\n" c.count "\\" #=> 2 c.count "\\A" #=> 0 c.count "X-\\w" #=> 3
Returns a 3-element array of substrings of self.
Matches a pattern against self, scanning from the beginning. The pattern is:
string_or_regexp itself, if it is a Regexp.
Regexp.quote(string_or_regexp), if string_or_regexp is a string.
If the pattern is matched, returns pre-match, first-match, post-match:
'hello'.partition('l') # => ["he", "l", "lo"] 'hello'.partition('ll') # => ["he", "ll", "o"] 'hello'.partition('h') # => ["", "h", "ello"] 'hello'.partition('o') # => ["hell", "o", ""] 'hello'.partition(/l+/) #=> ["he", "ll", "o"] 'hello'.partition('') # => ["", "", "hello"] 'тест'.partition('т') # => ["", "т", "ест"] 'こんにちは'.partition('に') # => ["こん", "に", "ちは"]
If the pattern is not matched, returns a copy of self and two empty strings:
'hello'.partition('x') # => ["hello", "", ""]
Related: String#rpartition, String#split.
Returns a 3-element array of substrings of self.
Matches a pattern against self, scanning backwards from the end. The pattern is:
string_or_regexp itself, if it is a Regexp.
Regexp.quote(string_or_regexp), if string_or_regexp is a string.
If the pattern is matched, returns pre-match, last-match, post-match:
'hello'.rpartition('l') # => ["hel", "l", "o"] 'hello'.rpartition('ll') # => ["he", "ll", "o"] 'hello'.rpartition('h') # => ["", "h", "ello"] 'hello'.rpartition('o') # => ["hell", "o", ""] 'hello'.rpartition(/l+/) # => ["hel", "l", "o"] 'hello'.rpartition('') # => ["hello", "", ""] 'тест'.rpartition('т') # => ["тес", "т", ""] 'こんにちは'.rpartition('に') # => ["こん", "に", "ちは"]
If the pattern is not matched, returns two empty strings and a copy of self:
'hello'.rpartition('x') # => ["", "", "hello"]
Related: String#partition, String#split.
Returns the Encoding object that represents the encoding of obj.
Returns a copy of self transcoded as determined by dst_encoding. By default, raises an exception if self contains an invalid byte or a character not defined in dst_encoding; that behavior may be modified by encoding options; see below.
With no arguments:
Uses the same encoding if Encoding.default_internal is nil (the default):
Encoding.default_internal # => nil s = "Ruby\x99".force_encoding('Windows-1252') s.encoding # => #<Encoding:Windows-1252> s.bytes # => [82, 117, 98, 121, 153] t = s.encode # => "Ruby\x99" t.encoding # => #<Encoding:Windows-1252> t.bytes # => [82, 117, 98, 121, 226, 132, 162]
Otherwise, uses the encoding Encoding.default_internal:
Encoding.default_internal = 'UTF-8' t = s.encode # => "Ruby™" t.encoding # => #<Encoding:UTF-8>
With only argument dst_encoding given, uses that encoding:
s = "Ruby\x99".force_encoding('Windows-1252') s.encoding # => #<Encoding:Windows-1252> t = s.encode('UTF-8') # => "Ruby™" t.encoding # => #<Encoding:UTF-8>
With arguments dst_encoding and src_encoding given, interprets self using src_encoding, encodes the new string using dst_encoding:
s = "Ruby\x99" t = s.encode('UTF-8', 'Windows-1252') # => "Ruby™" t.encoding # => #<Encoding:UTF-8>
Optional keyword arguments enc_opts specify encoding options; see Encoding Options.
Please note that, unless invalid: :replace option is given, conversion from an encoding enc to the same encoding enc (independent of whether enc is given explicitly or implicitly) is a no-op, i.e. the string is simply copied without any changes, and no exceptions are raised, even if there are invalid bytes.
Like encode, but applies encoding changes to self; returns self.