Splits str
into an array of tokens in the same way the UNIX Bourne shell does.
See Shellwords.shellsplit
for details.
Extracts data from self
.
If block
is not given, forming objects that become the elements of a new array, and returns that array. Otherwise, yields each object.
See Packed Data.
Like String#unpack
, but unpacks and returns only the first extracted object. See Packed Data.
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 string containing the characters in self
; the first character is upcased; the remaining characters are downcased:
s = 'hello World!' # => "hello World!" s.capitalize # => "Hello world!"
The casing may be affected by the given options
; see Case Mapping.
Related: String#capitalize!
.
Upcases the first character in self
; downcases the remaining characters; returns self
if any changes were made, nil
otherwise:
s = 'hello World!' # => "hello World!" s.capitalize! # => "Hello world!" s # => "Hello world!" s.capitalize! # => nil
The casing may be affected by the given options
; see Case Mapping.
Related: String#capitalize
.
Returns an array of substrings of self
that are the result of splitting self
at each occurrence of the given field separator field_sep
.
When field_sep
is $;
:
If $;
is nil
(its default value), the split occurs just as if field_sep
were given as a space character (see below).
If $;
is a string, the split occurs just as if field_sep
were given as that string (see below).
When field_sep
is ' '
and limit
is 0
(its default value), the split occurs at each sequence of whitespace:
'abc def ghi'.split(' ') # => ["abc", "def", "ghi"] "abc \n\tdef\t\n ghi".split(' ') # => ["abc", "def", "ghi"] 'abc def ghi'.split(' ') # => ["abc", "def", "ghi"] ''.split(' ') # => []
When field_sep
is a string different from ' '
and limit
is 0
, the split occurs at each occurrence of field_sep
; trailing empty substrings are not returned:
'abracadabra'.split('ab') # => ["", "racad", "ra"] 'aaabcdaaa'.split('a') # => ["", "", "", "bcd"] ''.split('a') # => [] '3.14159'.split('1') # => ["3.", "4", "59"] '!@#$%^$&*($)_+'.split('$') # => ["!@#", "%^", "&*(", ")_+"] 'тест'.split('т') # => ["", "ес"] 'こんにちは'.split('に') # => ["こん", "ちは"]
When field_sep
is a Regexp
and limit
is 0
, the split occurs at each occurrence of a match; trailing empty substrings are not returned:
'abracadabra'.split(/ab/) # => ["", "racad", "ra"] 'aaabcdaaa'.split(/a/) # => ["", "", "", "bcd"] 'aaabcdaaa'.split(//) # => ["a", "a", "a", "b", "c", "d", "a", "a", "a"] '1 + 1 == 2'.split(/\W+/) # => ["1", "1", "2"]
If the Regexp contains groups, their matches are also included in the returned array:
'1:2:3'.split(/(:)()()/, 2) # => ["1", ":", "", "", "2:3"]
As seen above, if limit
is 0
, trailing empty substrings are not returned:
'aaabcdaaa'.split('a') # => ["", "", "", "bcd"]
If limit
is positive integer n
, no more than n - 1-
splits occur, so that at most n
substrings are returned, and trailing empty substrings are included:
'aaabcdaaa'.split('a', 1) # => ["aaabcdaaa"] 'aaabcdaaa'.split('a', 2) # => ["", "aabcdaaa"] 'aaabcdaaa'.split('a', 5) # => ["", "", "", "bcd", "aa"] 'aaabcdaaa'.split('a', 7) # => ["", "", "", "bcd", "", "", ""] 'aaabcdaaa'.split('a', 8) # => ["", "", "", "bcd", "", "", ""]
Note that if field_sep
is a Regexp containing groups, their matches are in the returned array, but do not count toward the limit.
If limit
is negative, it behaves the same as if limit
was zero, meaning that there is no limit, and trailing empty substrings are included:
'aaabcdaaa'.split('a', -1) # => ["", "", "", "bcd", "", "", ""]
If a block is given, it is called with each substring and returns self
:
'abc def ghi'.split(' ') {|substring| p substring }
Output:
"abc" "def" "ghi" => "abc def ghi"
Note that the above example is functionally the same as calling each after split
and giving the same block. However, the above example has better performance because it avoids the creation of an intermediate array. Also, note the different return values.
'abc def ghi'.split(' ').each {|substring| p substring }
Output:
"abc" "def" "ghi" => ["abc", "def", "ghi"]
Related: String#partition
, String#rpartition
.
Returns an array of the characters in self
:
'hello'.chars # => ["h", "e", "l", "l", "o"] 'тест'.chars # => ["т", "е", "с", "т"] 'こんにちは'.chars # => ["こ", "ん", "に", "ち", "は"]
Concatenates each object in objects
to self
and returns self
:
s = 'foo' s.concat('bar', 'baz') # => "foobarbaz" s # => "foobarbaz"
For each given object object
that is an Integer
, the value is considered a codepoint and converted to a character before concatenation:
s = 'foo' s.concat(32, 'bar', 32, 'baz') # => "foo bar baz"
Related: String#<<
, which takes a single argument.
Returns 0 if self
is positive, Math::PI otherwise.
Returns:
1, if self
is Infinity
.
-1 if self
is -Infinity
.
nil
, otherwise.
Examples:
f = 1.0/0.0 # => Infinity f.infinite? # => 1 f = -1.0/0.0 # => -Infinity f.infinite? # => -1 f = 1.0 # => 1.0 f.infinite? # => nil f = 0.0/0.0 # => NaN f.infinite? # => nil
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 the dirpath
string that was used to create self
(or nil
if created by method Dir.for_fd
):
Dir.new('example').path # => "example"
Returns the real (absolute) pathname of pathname in the actual filesystem not containing symlinks or useless dots.
If dir_string is given, it is used as a base directory for interpreting relative pathname instead of the current directory.
All components of the pathname must exist when this method is called.
Returns the real (absolute) pathname of pathname in the actual filesystem. The real pathname doesn’t contain symlinks or useless dots.
If dir_string is given, it is used as a base directory for interpreting relative pathname instead of the current directory.
The last component of the real pathname can be nonexistent.
Returns the string representation of the path
File.path(File::NULL) #=> "/dev/null" File.path(Pathname.new("/tmp")) #=> "/tmp"
Splits the given string into a directory and a file component and returns them in a two-element array. See also File::dirname
and File::basename
.
File.split("/home/gumby/.profile") #=> ["/home/gumby", ".profile"]
Returns true
if the named file is writable by the effective user and group id of this process. See eaccess(3).
Note that some OS-level security features may cause this to return true even though the file is not writable by the effective user/group.
Returns true
if filepath
points to a character device, false
otherwise.
File.chardev?($stdin) # => true File.chardev?('t.txt') # => false
Returns the receiver.
string = "my string" string.itself.object_id == string.object_id #=> true
Return the arguments passed in as the third parameter to the constructor.
In the first form, returns an array of the names of all constants accessible from the point of call. This list includes the names of all modules and classes defined in the global scope.
Module.constants.first(4) # => [:ARGF, :ARGV, :ArgumentError, :Array] Module.constants.include?(:SEEK_SET) # => false class IO Module.constants.include?(:SEEK_SET) # => true end
The second form calls the instance method constants
.