Results for: "String#[]"

Returns nil, -1, or 1 depending on whether self is finite, -Infinity, or +Infinity.

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

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.

Returns an array of the entry names in the directory at dirpath; sets the given encoding onto each returned entry name:

Dir.entries('/example') # => ["config.h", "lib", "main.rb", "..", "."]
Dir.entries('/example').first.encoding
# => #<Encoding:UTF-8>
Dir.entries('/example', encoding: 'US-ASCII').first.encoding
# => #<Encoding:US-ASCII>

See String Encoding.

Raises an exception if the directory does not exist.

Import class refinements from module into the current class or module definition.

Synonym for $stdin.

Print an argument or list of arguments to the default output stream

cgi = CGI.new
cgi.print    # default:  cgi.print == $DEFAULT_OUTPUT.print

Returns a hash of values parsed from string according to the given format:

Date._strptime('2001-02-03', '%Y-%m-%d') # => {:year=>2001, :mon=>2, :mday=>3}

For other formats, see Formats for Dates and Times. (Unlike Date.strftime, does not support flags and width.)

See also strptime(3).

Related: Date.strptime (returns a Date object).

Returns a new Date object with values parsed from string, according to the given format:

Date.strptime('2001-02-03', '%Y-%m-%d')  # => #<Date: 2001-02-03>
Date.strptime('03-02-2001', '%d-%m-%Y')  # => #<Date: 2001-02-03>
Date.strptime('2001-034', '%Y-%j')       # => #<Date: 2001-02-03>
Date.strptime('2001-W05-6', '%G-W%V-%u') # => #<Date: 2001-02-03>
Date.strptime('2001 04 6', '%Y %U %w')   # => #<Date: 2001-02-03>
Date.strptime('2001 05 6', '%Y %W %u')   # => #<Date: 2001-02-03>
Date.strptime('sat3feb01', '%a%d%b%y')   # => #<Date: 2001-02-03>

For other formats, see Formats for Dates and Times. (Unlike Date.strftime, does not support flags and width.)

See argument start.

See also strptime(3).

Related: Date._strptime (returns a hash).

Returns a string representation of the date in self, formatted according the given format:

Date.new(2001, 2, 3).strftime # => "2001-02-03"

For other formats, see Formats for Dates and Times.

Returns false

Parses the given representation of date and time with the given template, and returns a hash of parsed elements. _strptime does not support specification of flags and width unlike strftime.

See also strptime(3) and strftime.

Parses the given representation of date and time with the given template, and creates a DateTime object. strptime does not support specification of flags and width unlike strftime.

DateTime.strptime('2001-02-03T04:05:06+07:00', '%Y-%m-%dT%H:%M:%S%z')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.strptime('03-02-2001 04:05:06 PM', '%d-%m-%Y %I:%M:%S %p')
                          #=> #<DateTime: 2001-02-03T16:05:06+00:00 ...>
DateTime.strptime('2001-W05-6T04:05:06+07:00', '%G-W%V-%uT%H:%M:%S%z')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.strptime('2001 04 6 04 05 06 +7', '%Y %U %w %H %M %S %z')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.strptime('2001 05 6 04 05 06 +7', '%Y %W %u %H %M %S %z')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
DateTime.strptime('-1', '%s')
                          #=> #<DateTime: 1969-12-31T23:59:59+00:00 ...>
DateTime.strptime('-1000', '%Q')
                          #=> #<DateTime: 1969-12-31T23:59:59+00:00 ...>
DateTime.strptime('sat3feb014pm+7', '%a%d%b%y%H%p%z')
                          #=> #<DateTime: 2001-02-03T16:00:00+07:00 ...>

See also strptime(3) and strftime.

Returns a string representation of self, formatted according the given +format:

DateTime.now.strftime # => "2022-07-01T11:03:19-05:00"

For other formats, see Formats for Dates and Times:

Works similar to parse except that instead of using a heuristic to detect the format of the input string, you provide a second argument that describes the format of the string.

Raises ArgumentError if the date or format is invalid.

If a block is given, the year described in date is converted by the block. For example:

Time.strptime(...) {|y| y < 100 ? (y >= 69 ? y + 1900 : y + 2000) : y}

Below is a list of the formatting options:

%a

The abbreviated weekday name (“Sun”)

%A

The full weekday name (“Sunday”)

%b

The abbreviated month name (“Jan”)

%B

The full month name (“January”)

%c

The preferred local date and time representation

%C

Century (20 in 2009)

%d

Day of the month (01..31)

%D

Date (%m/%d/%y)

%e

Day of the month, blank-padded ( 1..31)

%F

Equivalent to %Y-%m-%d (the ISO 8601 date format)

%g

The last two digits of the commercial year

%G

The week-based year according to ISO-8601 (week 1 starts on Monday and includes January 4)

%h

Equivalent to %b

%H

Hour of the day, 24-hour clock (00..23)

%I

Hour of the day, 12-hour clock (01..12)

%j

Day of the year (001..366)

%k

hour, 24-hour clock, blank-padded ( 0..23)

%l

hour, 12-hour clock, blank-padded ( 0..12)

%L

Millisecond of the second (000..999)

%m

Month of the year (01..12)

%M

Minute of the hour (00..59)

%n

Newline (n)

%N

Fractional seconds digits

%p

Meridian indicator (“AM” or “PM”)

%P

Meridian indicator (“am” or “pm”)

%r

time, 12-hour (same as %I:%M:%S %p)

%R

time, 24-hour (%H:%M)

%s

Number of seconds since 1970-01-01 00:00:00 UTC.

%S

Second of the minute (00..60)

%t

Tab character (t)

%T

time, 24-hour (%H:%M:%S)

%u

Day of the week as a decimal, Monday being 1. (1..7)

%U

Week number of the current year, starting with the first Sunday as the first day of the first week (00..53)

%v

VMS date (%e-%b-%Y)

%V

Week number of year according to ISO 8601 (01..53)

%W

Week number of the current year, starting with the first Monday as the first day of the first week (00..53)

%w

Day of the week (Sunday is 0, 0..6)

%x

Preferred representation for the date alone, no time

%X

Preferred representation for the time alone, no date

%y

Year without a century (00..99)

%Y

Year which may include century, if provided

%z

Time zone as hour offset from UTC (e.g. +0900)

%Z

Time zone name

%%

Literal “%” character

%+

date(1) (%a %b %e %H:%M:%S %Z %Y)

require 'time'

Time.strptime("2000-10-31", "%Y-%m-%d") #=> 2000-10-31 00:00:00 -0500

You must require ‘time’ to use this method.

Returns a string representation of self, formatted according to the given string format. See Formats for Dates and Times.

Behaves like IO.write, except that the stream is opened in binary mode with ASCII-8BIT encoding.

When called from class IO (but not subclasses of IO), this method has potential security vulnerabilities if called with untrusted input; see Command Injection.

Writes the given objects to the stream; returns nil. Appends the output record separator $OUTPUT_RECORD_SEPARATOR ($\), if it is not nil. See Line IO.

With argument objects given, for each object:

• Converts via its method to_s if not a string.

• Writes to the stream.

• If not the last object, writes the output field separator $OUTPUT_FIELD_SEPARATOR ($,) if it is not nil.

With default separators:

f = File.open('t.tmp', 'w+')
objects = [0, 0.0, Rational(0, 1), Complex(0, 0), :zero, 'zero']
p $OUTPUT_RECORD_SEPARATOR
p $OUTPUT_FIELD_SEPARATOR
f.print(*objects)
f.rewind
p f.read
f.close

Output:

nil
nil
"00.00/10+0izerozero"

With specified separators:

$\ = "\n"
$, = ','
f.rewind
f.print(*objects)
f.rewind
p f.read

Output:

"0,0.0,0/1,0+0i,zero,zero\n"

With no argument given, writes the content of $_ (which is usually the most recent user input):

f = File.open('t.tmp', 'w+')
gets # Sets $_ to the most recent user input.
f.print
f.close

Formats and writes objects to the stream.

For details on format_string, see Format Specifications.

Returns an array containing the elements in self, if a finite collection; raises an exception otherwise.

(1..4).to_a     # => [1, 2, 3, 4]
(1...4).to_a    # => [1, 2, 3]
('a'..'d').to_a # => ["a", "b", "c", "d"]

Returns the Encoding object that represents the encoding of obj.

Returns the values in self as an array:

Customer = Struct.new(:name, :address, :zip)
joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345)
joe.to_a # => ["Joe Smith", "123 Maple, Anytown NC", 12345]

Related: members.

Equivalent to self.to_s.encoding; see String#encoding.