Skip to content
ruby.help — home
documentation

Ruby 3.2

1,173 classes and modules
8,861 methods
Other versions: 4.1 · 4.0 · 3.4 · 3.3 · 3.1 · 3.0
recent

Text and data

String Mutable sequence of bytes with an encoding. Slicing, substitution, case, and Unicode. 148 instance methods, 2 class methods JSON Parse and generate JSON. Ships as a default gem. 10 instance methods, 7 class methods Regexp Regular-expression patterns. Match data, named captures, and flags. 20 instance methods, 11 class methods Symbol Immutable, interned names. One object per spelling. 31 instance methods, 2 class methods

Collections

Array Ordered, integer-indexed collection of any objects. 111 instance methods, 3 class methods Hash Ordered key-value map with default values and compare-by-identity. 73 instance methods, 5 class methods Enumerable Mixin that gives any class with each the full set of search, sort, and loop methods. 61 instance methods Range Interval from a start to an end, endless or beginless. 27 instance methods, 2 class methods Set Unordered collection of unique values, backed by Hash. 59 instance methods, 3 class methods

Numbers and time

Integer Arbitrary-precision whole numbers. Bit operations and iteration. 67 instance methods, 2 class methods Date Calendar dates without time. Civil, Julian, and ISO week forms. 68 instance methods, 33 class methods Time Point in time with zone. Parsing, formatting, and arithmetic. 65 instance methods, 16 class methods Float 64-bit floating-point numbers. Rounding, not-a-number, and infinity. 48 instance methods Numeric Base class of every number. Comparison, coercion, and stepping. 46 instance methods

Objects and control

Kernel Global functions every object has: puts, require, raise, loop. 86 instance methods, 2 class methods Object Default root. Equality, inspection, freezing, and message sending. 43 instance methods, 1 class methods BasicObject Blank-slate root above Object. Almost no methods, for proxies and domain-specific languages. 12 instance methods, 1 class methods Class A Module that makes instances. Inheritance, new, and allocate. 7 instance methods, 1 class methods Module Named collection of methods and constants. Mixins, visibility, and reflection. 77 instance methods, 5 class methods Proc Callable block with a binding. Lambdas, currying, and arity. 19 instance methods, 1 class methods Struct Generate a value class with named members in one line. 23 instance methods, 4 class methods

Input and output

Dir Directory listing and globbing. 14 instance methods, 21 class methods File Input and output on a path. Reading, writing, file status, and permissions. 10 instance methods, 63 class methods IO Byte and line streams. Files, pipes, sockets, and the console. 116 instance methods, 18 class methods

Concurrency

Thread Concurrent execution, one thread running Ruby at a time. Queues, mutexes, and thread-local values. 37 instance methods, 19 class methods
Abbrev Calculates the set of unambiguous abbreviations for a given set of strings. 1 instance methods, 1 class methods ACL Simple Access Control Lists. 3 instance methods, 1 class methods Addrinfo 42 instance methods, 7 class methods ARGF The files named on the command line, read as one stream. 50 instance methods ArgumentError Raised when the arguments are wrong and there isn’t a more specific Exception class. 0 instance methods Base64 The Base64 module provides for the encoding ( encode64, strict_encode64, urlsafe_encode64 ) and decoding ( decode64, strict_decode64, urlsafe_decode64 ) of 6 instance methods BasicSocket BasicSocket is the super class for all the Socket classes. 20 instance methods, 3 class methods Benchmark The Benchmark module provides methods to measure and report the time used to execute Ruby code. 5 instance methods, 5 class methods BigDecimal Arbitrary-precision decimal numbers, from the bigdecimal gem. 61 instance methods, 9 class methods BigMath Provides mathematical functions. 6 instance methods, 2 class methods Binding A captured execution context. Local variables, self, and eval. 8 instance methods CGI Since Ruby 4.0, only the escape helpers from CGI::Escape. The rest of CGI left the standard library. 8 instance methods, 4 class methods ClosedQueueError The exception class which will be raised when pushing into a closed Queue. 0 instance methods Comparable Mixin that derives the ordering operators from <=>. 7 instance methods Complex Complex numbers in rectangular or polar form. 40 instance methods, 4 class methods Continuation Saved point of execution from Kernel#callcc, after require "continuation". 2 instance methods CoreExtensions Namespace for the RubyGems patches to core classes. 0 instance methods Coverage Coverage provides coverage measurement feature for Ruby. 0 instance methods, 10 class methods CSV If you are familiar with CSV data and have a particular task in mind, you may want to go directly to the: 56 instance methods, 13 class methods Data Immutable value class with named members, defined in one line. 10 instance methods, 3 class methods DateTime A subclass of Date that easily handles date, hour, minute, second, and offset. 22 instance methods, 17 class methods Delegator Base class that passes method calls on to a wrapped object. See SimpleDelegator and DelegateClass. 17 instance methods, 1 class methods DidYouMean The DidYouMean gem adds functionality to suggest possible method/class names upon errors such as NameError and NoMethodError. 0 instance methods, 4 class methods Digest Framework for message digest algorithms such as SHA-256 and MD5. 0 instance methods, 2 class methods DRb dRuby is a distributed object system for Ruby. 15 instance methods, 15 class methods Encoding Character encodings and the rules for converting between them. 7 instance methods, 10 class methods EncodingError EncodingError is the base class for encoding errors. 0 instance methods English Include the English library file in a Ruby script, and you can reference the global variables such as $_ using less cryptic names, listed below. 0 instance methods Enumerator A class which allows both internal and external iteration. 14 instance methods, 3 class methods ENV The environment variables of the process, as a Hash-like object. 0 instance methods, 49 class methods
EOFError Raised by some IO operations when reaching the end of file. 0 instance methods ERB ERB provides an easy to use but powerful templating system for Ruby. 10 instance methods, 2 class methods Errno One exception class per operating-system error code. 0 instance methods ErrorHighlight Points at the exact expression that failed, under the line in an error message. 0 instance methods, 3 class methods Etc The Etc module provides access to information typically stored in files in the /etc directory on Unix systems. 0 instance methods, 19 class methods Exception Root of the error hierarchy. Backtraces, causes, and messages. 13 instance methods, 4 class methods FalseClass The one false object. 6 instance methods fatal fatal is an Exception that is raised when Ruby has encountered a fatal error and must exit. 0 instance methods Fcntl Constants from the C header fcntl.h, for IO#fcntl and open(2) flags. 0 instance methods Fiber Cooperative coroutines. Suspend and resume by hand or with a scheduler. 11 instance methods, 11 class methods FiberError Raised for an invalid Fiber operation, such as resuming a dead fiber. 0 instance methods Fiddle A libffi wrapper for Ruby. 1 instance methods, 12 class methods FileTest FileTest implements file test operations similar to those used in File::Stat. 26 instance methods FileUtils Namespace for file utility methods for copying, moving, removing, etc. 50 instance methods, 52 class methods Find The Find module supports the top-down traversal of a set of file paths. 2 instance methods, 2 class methods FloatDomainError Raised when attempting to convert special float values (in particular Infinity or NaN ) to numerical classes which don’t support them. 0 instance methods Forwardable The Forwardable module provides delegation of specified methods to a designated object, using the methods def_delegator and def_delegators. 6 instance methods FrozenError Raised when there is an attempt to modify a frozen object. 1 instance methods, 1 class methods GC Start, tune, and measure the garbage collector. 1 instance methods, 24 class methods Gem RubyGems is the Ruby standard for publishing and managing third party libraries. 0 instance methods, 102 class methods GetoptLong Class GetoptLong provides parsing both for options and for regular arguments. 10 instance methods, 1 class methods IndexError Raised when the given index is invalid. 0 instance methods Interrupt Raised when the interrupt signal is received, typically because the user has pressed Control-C (on most posix platforms). 0 instance methods IOError Raised when an IO operation fails. 0 instance methods IPAddr IPAddr provides a set of methods to manipulate an IP address. 46 instance methods, 3 class methods IPSocket IPSocket is the super class of TCPSocket and UDPSocket. 4 instance methods, 3 class methods Jacobian require ‘bigdecimal/jacobian’ 3 instance methods Kconv Kanji Converter for Ruby. 13 instance methods, 13 class methods KeyError Raised when the specified key is not found. 2 instance methods, 1 class methods LoadError Raised when a file required (a Ruby script, extension library, …) fails to load. 0 instance methods
ACL::ACLEntry An entry in an ACL 3 instance methods, 1 class methods ACL::ACLList A list of ACLEntry objects. 2 instance methods, 1 class methods Benchmark::Tms A data object, representing the times associated with a benchmark measurement. 11 instance methods, 1 class methods CGI::Cookie Class representing an HTTP cookie. 9 instance methods, 2 class methods CGI::Escape 6 instance methods CGI::HTML3 0 instance methods CGI::HTML4 0 instance methods CGI::HTML4Fr 0 instance methods CGI::HTML4Tr 0 instance methods CGI::HTML5 0 instance methods CGI::HtmlExtension Mixin module providing HTML generation methods. 22 instance methods CGI::InvalidEncoding Exception raised when there is an invalid encoding detected 0 instance methods CGI::QueryExtension Mixin module that provides the following: 12 instance methods CGI::Session This file provides the CGI::Session class, which provides session support for CGI scripts. 6 instance methods, 1 class methods CGI::Session::FileStore File-based session storage class. 4 instance methods, 1 class methods CGI::Session::MemoryStore In-memory session storage class. 4 instance methods, 1 class methods CGI::Session::NullStore Dummy session storage class. 4 instance methods, 1 class methods CGI::Session::PStore PStore-based session storage class. 4 instance methods, 1 class methods CGI::Util 15 instance methods CoreExtensions::TCPSocketExt RubyGems patch that prepends a faster connect to TCPSocket. 0 instance methods, 1 class methods CoreExtensions::TCPSocketExt::Initializer TCPSocket.new that tries each resolved address and keeps the first to connect. 0 instance methods, 1 class methods CSV::DeleteSuffix 1 instance methods CSV::FieldsConverter Note: Don’t use this class directly. 7 instance methods, 1 class methods CSV::InputRecordSeparator 0 instance methods, 1 class methods CSV::MalformedCSVError The error thrown when the parser encounters illegal CSV formatting. 0 instance methods, 1 class methods CSV::MatchP 1 instance methods CSV::Parser Note: Don’t use this class directly. 52 instance methods, 1 class methods CSV::Parser::InputsScanner CSV::InputsScanner receives IO inputs, encoding and the chunk_size. 13 instance methods, 1 class methods CSV::Parser::InvalidEncoding Raised when encoding is invalid. 0 instance methods CSV::Parser::Scanner CSV::Scanner receives a CSV output, scans it and return the content. 5 instance methods, 1 class methods
CSV::Parser::UnexpectedError Raised when unexpected case is happen. 0 instance methods CSV::Row A CSV::Row instance represents a CSV table row. 32 instance methods, 1 class methods CSV::Table A CSV::Table instance represents CSV data. 21 instance methods, 1 class methods CSV::Writer Note: Don’t use this class directly. 9 instance methods, 1 class methods Date::Error Raised for an invalid date or time. 0 instance methods DidYouMean::ClassNameChecker Suggests similar constant names for a NameError. 3 instance methods, 1 class methods DidYouMean::ClassNameChecker::ClassName A candidate constant name with its namespace. 1 instance methods, 1 class methods DidYouMean::Correctable Mixin that adds "Did you mean?" suggestions to an error message. 5 instance methods DidYouMean::Formatter The DidYouMean::Formatter is the basic, default formatter for the gem. 1 instance methods, 1 class methods DidYouMean::Jaro Jaro similarity between two strings. 1 instance methods DidYouMean::JaroWinkler Jaro-Winkler similarity, which favours a shared prefix. 1 instance methods DidYouMean::KeyErrorChecker Suggests similar keys for a KeyError. 2 instance methods, 1 class methods DidYouMean::MethodNameChecker Suggests similar method names for a NoMethodError. 3 instance methods, 1 class methods DidYouMean::NameErrorCheckers Picks the checker for a NameError, by constant or by variable name. 0 instance methods, 1 class methods DidYouMean::NullChecker The checker that suggests nothing. 1 instance methods, 1 class methods DidYouMean::PatternKeyNameChecker Suggests similar keys for a NoMatchingPatternKeyError. 2 instance methods, 1 class methods DidYouMean::PlainFormatter The DidYouMean::Formatter is the basic, default formatter for the gem. 1 instance methods, 1 class methods DidYouMean::RequirePathChecker Suggests similar paths for a failed require. 1 instance methods, 2 class methods DidYouMean::SpellChecker Ranks a dictionary of words by distance to a misspelling. 1 instance methods, 1 class methods DidYouMean::TreeSpellChecker Spell checker for a dictionary with a tree structure, such as file paths. 13 instance methods, 1 class methods DidYouMean::VariableNameChecker Suggests similar variable and method names for a NameError. 1 instance methods, 1 class methods DidYouMean::VerboseFormatter The DidYouMean::Formatter is the basic, default formatter for the gem. 1 instance methods, 1 class methods Digest::Base This abstract class provides a common interface to message digest implementation classes written in C. 5 instance methods Digest::Class Base class of the digest algorithm classes. 0 instance methods, 5 class methods Digest::Instance Methods every digest object has: update, digest, and hexdigest. 20 instance methods Digest::MD5 A class for calculating message digests using the MD5 Message-Digest Algorithm by RSA Data Security, Inc., described in RFC1321. 0 instance methods Digest::RMD160 A class for calculating message digests using RIPEMD-160 cryptographic hash function, designed by Hans Dobbertin, Antoon Bosselaers, and Bart Preneel. 0 instance methods Digest::SHA1 SHA-1 message digests. Not safe where collisions matter. 0 instance methods Digest::SHA2 A meta digest provider class for SHA256, SHA384 and SHA512. 5 instance methods, 1 class methods DRb::DRbArray An Array wrapper that can be sent to another server via DRb. 0 instance methods, 1 class methods