Content: [ String
text ]
| RelationalExpr
(‘<’ | ‘>’ | ‘<=’ | ‘>=’) AdditiveExpr
| AdditiveExpr
| FUNCTION_NAME ‘(’ ( expr ( ‘,’ expr )* )? ‘)’
Explanation of the conflict used by exceptions to print useful messages
Tries to convert obj
into an array, using the to_ary
method. Returns the converted array or nil
if obj
cannot be converted. This method can be used to check if an argument is an array.
Array.try_convert([1]) #=> [1] Array.try_convert("1") #=> nil if tmp = Array.try_convert(arg) # the argument is an array elsif tmp = String.try_convert(arg) # the argument is a string end
Replaces the contents of self
with the contents of other_ary
, truncating or expanding if necessary.
a = [ "a", "b", "c", "d", "e" ] a.replace([ "x", "y", "z" ]) #=> ["x", "y", "z"] a #=> ["x", "y", "z"]
By using binary search, finds an index of a value from this array which meets the given condition in O(log n) where n is the size of the array.
It supports two modes, depending on the nature of the block. They are exactly the same as in the case of the bsearch
method, with the only difference being that this method returns the index of the element instead of the element itself. For more details consult the documentation for bsearch
.
Returns the factorization of self
.
See Prime#prime_division
for more details.
Try to convert obj into a String
, using to_str
method. Returns converted string or nil if obj cannot be converted for any reason.
String.try_convert("str") #=> "str" String.try_convert(/re/) #=> nil
Replaces the contents of str with the corresponding values in other_str.
s = "hello" #=> "hello" s.replace "world" #=> "world"
Returns an array of grapheme clusters in str. This is a shorthand for str.each_grapheme_cluster.to_a
.
If a block is given, which is a deprecated form, works the same as each_grapheme_cluster
.
Converts a pathname to an absolute pathname. Relative paths are referenced from the current working directory of the process unless dir_string
is given, in which case it will be used as the starting point. The given pathname may start with a “~
”, which expands to the process owner’s home directory (the environment variable HOME
must be set correctly). “~
user” expands to the named user’s home directory.
File.expand_path("~oracle/bin") #=> "/home/oracle/bin"
A simple example of using dir_string
is as follows.
File.expand_path("ruby", "/usr/bin") #=> "/usr/bin/ruby"
A more complex example which also resolves parent directory is as follows. Suppose we are in bin/mygem and want the absolute path of lib/mygem.rb.
File.expand_path("../../lib/mygem.rb", __FILE__) #=> ".../path/to/project/lib/mygem.rb"
So first it resolves the parent of __FILE__, that is bin/, then go to the parent, the root of the project and appends lib/mygem.rb
.
Returns whether ASCII-compatible or not.
Encoding::UTF_8.ascii_compatible? #=> true Encoding::UTF_16BE.ascii_compatible? #=> false
Sets the named constant to the given object, returning that object. Creates a new constant if no constant with the given name previously existed.
Math.const_set("HIGH_SCHOOL_PI", 22.0/7.0) #=> 3.14285714285714 Math::HIGH_SCHOOL_PI - Math::PI #=> 0.00126448926734968
If sym
or str
is not a valid constant name a NameError
will be raised with a warning “wrong constant name”.
Object.const_set('foobar', 42) #=> NameError: wrong constant name foobar
Return the number of seconds the specified time zone differs from UTC.
Numeric
time zones that include minutes, such as -10:00
or +1330
will work, as will simpler hour-only time zones like -10
or +13
.
Textual time zones listed in ZoneOffset are also supported.
If the time zone does not match any of the above, zone_offset
will check if the local time zone (both with and without potential Daylight Saving Time changes being in effect) matches zone
. Specifying a value for year
will change the year used to find the local time zone.
If zone_offset
is unable to determine the offset, nil will be returned.
require 'time' Time.zone_offset("EST") #=> -18000
You must require ‘time’ to use this method.
Try to convert obj into an IO
, using to_io
method. Returns converted IO
or nil
if obj cannot be converted for any reason.
IO.try_convert(STDOUT) #=> STDOUT IO.try_convert("STDOUT") #=> nil require 'zlib' f = open("/tmp/zz.gz") #=> #<File:/tmp/zz.gz> z = Zlib::GzipReader.open(f) #=> #<Zlib::GzipReader:0x81d8744> IO.try_convert(z) #=> #<File:/tmp/zz.gz>
Provides marshalling support for use by the Marshal
library.
Provides marshalling support for use by the Marshal
library.
Try to convert obj into a Regexp
, using to_regexp method. Returns converted regexp or nil if obj cannot be converted for any reason.
Regexp.try_convert(/re/) #=> /re/ Regexp.try_convert("re") #=> nil o = Object.new Regexp.try_convert(o) #=> nil def o.to_regexp() /foo/ end Regexp.try_convert(o) #=> /foo/
Clone internal hash.