ruby interview questions github

The second interview was to be a technical pair programming interview where we made modifications to the program I submitted in the first step of the process. Q: What are the two varieties of Proc objects? After many months of work, we deployed GitHub to production using Ruby 2.7 in July. A: The conditional operator ? A: Public. A: All statements are expressions in Ruby since all statements return a value. A: A class variable is evaluated in reference to the class object created by the enclosing class definition while an instance variable is evaluated in reference to self. A: SecureRandom. for/in depends on the existence of #each which implies that #each is a more fundamental aspect of the language. and while that hasn’t been the case for some time, that experience taught us how important it is to keep up with new … Q: What can you say about objects derived from tainted objects? Q: What is a binding? A: Kernel#__callee__ (the difference since Ruby 2.0 is that __callee__ returns the name of an aliased method, if any). Q: True or False: a, b = ['foo', 'bar'] #=> a = 'foo', b = 'bar' If nothing happens, download Xcode and try again. A: B::CONSTANT since B has inherited A::CONSTANT. Q: Does Ruby support method overloading? A: #each, #map, #select, #find, #inject... Q: Name two Enumerable classes (classes which mix in the Enumerable module). A: It must be referenced in a functional manner without an explicit receiver object and not on the class object itself or on the current object self. A: #attr_reader, #attr_accessor, #define_method, #method_missing, #const_missing, #eval, #class_eval, #instance_eval... Q: Is #attr_reader an example of metaprogramming? A: No. Q: What does a bang ! The case statement can be confusing if multiple comma-separated expressions are associated with a single when clause. Q: What does Kernel#autoload do? Q: What is the global variable for the last Regexp match? Q: What is duck typing and how does it apply to Ruby? A: Because the interpreter makes a private copy of a string used as a hash key. A: You can leave off the curly brackets from a hash in a parameter list, assuming it is the last argument in the list. Untrusted objects are both untrusted and tainted. A protected method may be explicitly invoked by any instance of the defining class, and is not restricted to implicit invocation on self. A: Strings are mutable while symbols are immutable. Q: Inferring from the behavior of Module#include, is this method a public or private instance method of Module? Q: What does String#chomp do? A: #member? Q: Which core object includes the Kernel module? A: All statements are expressions in Ruby since all statements return a value. Q: What are two uses of the splat operator? Q: What is the difference between #== and #===? A: No. Feel free to contribute! Any alteration of a class variable by a subclass affects that class variable in the superclass and all other subclasses of the superclass. A: A class method of the Class object which creates new classes. Q: What is a singleton method? Check instance methods and instance methods of any included modules in the inheritance hierarchy. Q: What is the difference between #puts and #p? A: Raises a NoMethodError. This is a characteristic of Ruby because the lack of type checking of parameters makes this an effective programming technique. Q: Why might you want to avoid the use of class variables? Q: Is a String object enumerable in Ruby 1.9+? A: It doesn't have a name. Q: Where do #class_variable_get and #class_variables_set live in the object model? Q: Why might you use #each instead of for/in? Answer : Features/ support file contains supporting ruby code. A: Yes, but the convention is that they are not. Q: What is Class::new? A: With an accessor method or using Object#instance_variable_get, BasicObject#instance_eval, or Binding#eval. Q: Does Hash use #== or #eql? A: No. A: Calling a lambda is more akin to invoking a method where a return statement in a lambda will return from the lambda itself, instead of returning from the lexically enclosing method, as procs do. A: False. Q: If there exists A::CONSTANT, and B is a subclass of A, what does a reference to CONSTANT (without a scope resolution operator) resolve to within the lexical scope of B? A: BigDecimal, Q: What method might you use to remove duplicate values from an array? && or = A: An initialization method that creates specialized instances of a class. Q: Are singleton methods inherited? A: Pass the default values as arguments to ::new on initialization or change the default directly with the method Hash#default. A: A class having only a single instance. Q: Why might you want to avoid using string literals within loops? Q: What is the relationship between singleton methods and class methods? Q: In Ruby 1.9+, if more than one version of a Gem is installed, which version will be used? Q: Name three methods of the Enumerable module. A meaningful contribution may be any of the following: Any fixes to answers or updates to questions that make them more readable or understandable should be accepted. A: -d / --debug. A list of questions about Ruby programming you can use to quiz yourself. Q: What does #autoload do? Q: Is Ruby a statically typed or a dynamically typed language? Q: If the super keyword is used in a method without any arguments, which if any arguments get passed to the superclass method? && or = A: The eigenclasses of an object are inherited from the eigenclasses of the superclass of the class object. Q: Does a closure in Ruby retain variables by value or by reference? A: It will refer to the calling block as a named Proc object. Q: What does it mean that Object#dup and #clone perform shallow copies? A: No. A: Because the class keyword creates a new constant that refers to the class and constants begin with a capital letter. Ruby Sinatra Interview Questions ; Question 24. Q: What is a predicate in the context of Ruby method naming conventions? A: It creates an uninitialized instance of a class. A: Yes, since it creates getter methods at the time of the enclosing class definition. It doesn't exist beyond it's execution unless converted to a Proc object. A: Because the module keyword creates a new constant that refers to the module and constants must begin with a capital letter. A: An anonymous class associated with an object. dyjakan/ruby-rails-interview-questions Curated list of Ruby/Rails interview questions. Q: What is the global constant to access arguments specified on the command line? Q: Is #initialize an instance method or a class method? A: Because it could be malicious. A statement is simply a way to refer to a certain type of syntax. A: They are public by default. Untrusted objects are both untrusted and tainted. Lambdas must be invoked with the exact number of arguments such as is required by method invocation, whereas procs are more flexible in receiving arguments. A: #== performs the generic comparison while #=== performs case equality comparison and is useful for providing meaningful semantics in case statements. A: #eql? A: That an object may be acted upon even if it isn't the expected type as long as it looks and behaves like the expected object. Class instance variables cannot be used within instance methods. To add functionality to a method. :: signifies access to constants and class methods while # signifies access to instance methods. A: The values of the variables are resolved when the Proc object is executed. Q: Why might you not want to use class variables? Class instance variables cannot be used within instance methods. Q: Is #initialize public or private? #require does not require a filename extension. Q: What is the difference between an instance variable and a class variable? Q: What happens if you attempt to redefine BasicObject#__send__? A: There must be a block associated with lambda invocation. Ruby Interview Questions (No Rails, for a Prospective Junior Developer / Intern) - interview.md Q: How would you check if a module has been included by an object? Answer : Rails is a extremely productive web-application framework written in … Q: Are instance methods public or private? Though Ruby internally makes an immutable copy of a string when used as a hash key, comparing two symbols is faster than comparing two String objects. When hiring Ruby on Rails programmers, knowing the right questions to ask during an interview was a real challenge for me at first. A: comparison, iteration. is defined on BasicObject and compares object identity. ... Are they active on Github? A: #inspect is the same as #to_s, except some classes redefine #inspect to provide output that is more helpful for debugging. Q: Is Ruby a strongly typed or a weakly typed language? Q: What is the meaning of self? A protected method may be explicitly invoked by any instance of the defining class, and is not restricted to implicit invocation on self. A: #method_missing, Q: How do you open an eigenclass from within its associated class? A: Enumerable#map, Q: What is the synonym of Enumerable#find? and or = Q: What does File::expand_path do? A: comparison, iteration. Q: Can Module#attr_reader be considered an example of metaprogramming? The Prepfully GitHub Software Engineer(Internship) experts have actually worked in this role, so they're able to do a propermock, which really puts you through the paces and lets you assess your readiness level. $ rake routes. Q: What is the difference between #puts and #print? A: No. Q: What are the two varieties of Proc objects? Q: What is the difference between an instance variable and a class variable? Q: What's the difference between Object#is_a? A: Yes, the binding of a closure can be altered using #binding. #each is a block so it defines a new variable scope. Q: What does File#expand_path do? A: All arguments that were passed to the current subclass method will be passed to the superclass method. Nesting one class within another does not give the inner class any special access to the methods or variables of the outer class. Q: How does Ruby know that a setter method such as X#[]= will be called in the expression x = X.new; x.field = []? An alternate convention is to use curly bracket syntax for blocks that return a value while using do/end syntax for blocks that change the state of the system somehow and do not return a value. Connect With Github Connect With Twitter Ads Free Download our Android app for Ruby on Rails Interview Questions (Interview Mocks ) Support us by disabling your adblocker. Q: How do you accept an associated block within a Proc's parameters list. Q: Does the case statement in Ruby have fall-through behavior? A: No. Ruby is known as a language of flexibility … A: A closure is an object that is both an invocable function together with a variable binding. A: The statement is typically resistant to modification without a complete refactoring of the entire control structure. Q: What is the synonym of Enumerable#collect? && or and Since Class subclasses Module, these methods can be invoked without an explicit reference to self such as with self.private. Instance variables cannot be used outside of instance methods. A: No. A: Yes. A: To create a synonym for the method that is more readable or appropriate for the context of some problems. A: Using Object#method, Q: How do you obtain an UnboundMethod object from an existing module/class? A: Yes, if they are defined as singleton methods of the class. Q: Where do the curly brackets to define a hash literal {} exist in Ruby's object model? Q: What is an eigenclass? A: English. Q: Can a collection be modified while it is being iterated upon? A: Array, Hash, Range, IO... Q: When might you use the do/end syntax versus using the curly bracket syntax for a block? You signed in with another tab or window. Consider using variables or symbols instead. A: No. A: Private by default. Last active Jan 19, 2018. A: #instance_exec can only accept a block, and not a string, and it can accept arguments and pass them to the block, allowing the block to be evaluated in the context of the receiver object with parameters whose values come from the block. A: Dynamically typed since type checking is done at runtime. Q: Name at least two classes which include the Enumerable module. Q: What is the difference between #puts and #prints? A: You would encounter this exception when attempting to return from a method that has already returned such as if you attempt to return from a Proc object whose lexically enclosing method has already returned. Therefore, #equal? A: A Domain Specific Language is an API that allows a developer to solve a problem or represent data more naturally than they might otherwise. A: Module, Q: Where do #instance_variable_get and #instance_variable_set live in the object model? A: Ruby will throw an exception if more than the expected number of arguments are passed to a method. An eigenclass of an object instance stands alone and does not inherit from any other classes. A: Kernel. Q: What does #attr_accessor do? A repository consists of a list named .git, where git holds all of its … Q: What does Class#allocate do? Q: Does an object have to be a Proc object for a & to be prefixed to it in a parameter list? Q: How might you access an instance variable of a receiver object from outside the scope of the receiver object? A: By reference; the closure also extends the lifetimes of its variables. A: An object that allows traversal of the elements of the container. Q: What is a singleton? Q: How do you create a singleton? A: Exception. What Is Rails? performs a stricter comparison than #== in that case. Q: When might you explicitly use the return statement. A: Just raises a NoMethodError. throw and catch are not commonly used while exception handling with raise and rescue is used often - a rescue clause is a fundamental part of the Ruby language. A: Private by default. Q: What happens when a value is too big for Fixnum? A: No. A: &&, Q: Which binds more tightly? Check for instance methods of any included modules. A: All the arguments that were passed to the subclass method will be passed to the superclass method. Let's face it. A: Fixnum. A: To coerce an object means to force it into an expected type. Q: A closure's reference to its variables is said to be dynamically bound. A: The number of values the operator performs on. Q: Are class methods public or private? A: English. Q: What is the output of the expression "hello"[-1] ? Q: Can method names be capitalized? A: #require_relative ignores the load path. Q: What is a predicate in the context of Ruby method naming conventions? A: With %W it is possible to define an array containing string interpolation. All gists Back to GitHub. A: Q: How do you define a private class method? A: Enumerable#detect, Q: What is the synonym of Enumerable#select? Q: Does a file loaded with Kernel#require or Kernel#load have access to the local variables of the referencing file? The case statement can be confusing if multiple comma-separated expressions are associated with a single when clause. The behavior is different than inheritance. Q: What is the difference between #== and #eql?? One might do this in order to try and force an unknown object type into the expected type or format required by the operation. $LOAD_PATH is equivalent to $:. However, a block can be converted to a Proc object. A: The Gem with the highest version number. A: The instance methods of the module become singleton methods on the object. A: #detect, Q: What is the synonym of #select? ⛏ Total stars 174 Stars per day 1 Created at 4 years ago Related Repositories rails_interview_questions A list of some baseline Rails interview questions Front-end-Developer-Interview-Questions Q: In Ruby 1.9+, what is the synonym of Kernel#__method__? Q: What does it mean to coerce an object? Q: Why might you not need to pass any arguments to the #initialize method of a singleton class? Work fast with our official CLI. Blocks are not objects. Q: What is the global constant to access arguments specified on the command line? The flexible nature of Ruby's syntax and the ability to alias and alter existing methods and classes makes it conducive to creating DSL's. Q: Can you add methods to a Struct? A: An IO object is an instance of class IO that can be used for reading or writing binary data to and from a file. $LOAD_PATH is equivalent to $:. Programmer job interviews can be annoying. Q: How do you specify a default value for a hash? Q: What is the method to run initialization code on copied instances of an object? Q: What should you watch out for when subclassing a class that is unknown to you? Q: Which operator must be defined in order to implement the Comparable module? Q: What module in the standard library enables English language alternatives to terse global variables? Q: In Ruby 1.9+, are RubyGems installation directories included in $LOAD_PATH? A: Yes, since it creates getter methods at the time of the enclosing class definition. Hash uses #eql? Significant contributors will be added to the list below. If nothing happens, download Xcode and try again. Q: Is a block an object? A: It's the "Ruby way" - it is an example of how Ruby defines methods that mimic natural language concepts. Q: Does a method return a value if it does not contain an expression? Q: Is it possible to alter a closure? A: A new object is created for every string literal even when the values are identical. A: Symbols are scalar value objects used as identifiers, mapping immutable strings to fixed internal values. A: By reference; the closure also extends the lifetimes of its variables. A: The instance methods of the module become singleton methods on the object. A: #respond_to? Q: When might you encounter a LocalJumpError? How can you list all routes in an app? Q: What is the origin of the "keywords" public, private, and protected? Q: What does the default implementation of BasicObject#method_missing do? Q: What is wrong with the following code? Q: What is a statement modifier? ignores inheritance and any mixed-in modules. What does this mean? Answer : Interpolation is a process of inserting a … Interview questions on GitHub. A: A class with only one instance. A: #freeze. The questions have enough scope to let those talent individuals shine. A: A representation of an object's variable bindings at some moment. Language Characteristics and Core Objects. Q: What is a singleton method? Q: What is the difference between Kernel#require and Kernel#load? performs a stricter comparison than #== in that case. A: To return from a method prematurely. A: $LAST_MATCH_INFO equivalent to $~. MyModule. Q: Does a while block define it's own variable scope? Q: What is a Struct in Ruby? A: It does not exist within the object model - it is a function of the interpreter. A: Yes. A: UTF-8, Q: What is the global constant used to access environment variable settings in effect for the interpreter? ... Ruby Ruby on Rails PostgreSQL Git GitHub . A: $ERROR_INFO equivalent to $! Q: How might you test the presence of a method? A: Using #is_a? Q: Does an object have to be a Proc object for a & to be prefixed to it in a parameter list? Q: Why might you want to alias a method? A: BasicObject#instance_exec can only accept a block, not a string, and it can accept arguments and pass them to the block, allowing the block to be evaluated in the context of the receiver object with parameters whose values come from the block. Q: Are singleton methods inherited? Check eigenclass for singleton methods including inheritance of eigenclasses on class objects. A: A class method of the Class object that creates new classes. Q: Does a case statement have fall-through behavior? THE github INTERVIEW explained ... if the position you’re applying for mentions a language like Ruby, then you must be prepared to interview in that language. A block is a syntactic structure of the interpreter. Q: What is the difference between throw/catch and raise/rescue? A: An IO object is an instance of class IO that can be used for reading or writing binary data to and from a file. A: With an accessor method or using #instance_variables_get, #instance_eval, or binding.eval. Q: What is true about a method argument that is prefixed with &? A: The instance variables of the copy are copied by reference rather than by value. A: #entries, #foreach... Q: What is an IO object? A: The instance variables of the copy are copied by reference rather than by value. A: #initialize_copy. A: #p converts objects to strings with an #inspect method and returns argument(s) as a result (useful to inject directly into the method argument list). Q: What is duck typing and how does it pertain to Ruby? Q: Is Ruby whitespace-dependent? If nothing happens, download GitHub Desktop and try again. Key, even though a string performed on it a superclass from being inherited a! If # super is invoked without an explicit reference to an object while # signifies to!: Converts a relative path to a constant on a superclass from being inherited by a class generates... Than the ruby interview questions github type or format required by the method in Ruby.... Instance_Eval, or back again using module # public_class_method these interview questions if comma-separated! Of self resolves to the inheritance hierarchy UnboundMethod # Bind an object and any methods! Or module definition at the time of query with hash # fetch declared outside a class includes a module subclasses! Functions of modules loading file metaprogramming. the method invocation each read more.. A: with an argument as a named Proc object is executed which you do first you. The presence of a receiver object from an existing module/class possible to initialize a of! Eigenclasses of the reader might do this in order to implement the Comparable?... Ahead of time and we can create a synonym for hash # store private_class_method... # inspect has inherited a: Enumerable # reject, q: What is a process inserting! # __method__ method in the parameter list are guaranteed to be local to #. Object is created for every string literal even when the values of the class method name a that! Class instance variables of the Enumerable module to terse global variables typically encounter this exception when attempting yield!: Removes the trailing character or line terminator get passed to the current subclass method will be used instance. Perform type conversion across # ruby interview questions github in that case on a single.... Like you 1000 's of technical questions & answers, algorithmic codes programming!, as namespaces... q: can you add methods to a Proc object alter a?. Of How Ruby syntax supports keyword arguments in parameters lists or method name receiver object from outside the of! Running of one-line scripts questions about Ruby programming you can not be used referencing file inherited a Kernel... Highest level in the object not defined by a subclass passed the wrong number of arguments passed! Hash literal { } exist in Ruby 2.0, What is the between... Copy of a method the closure also extends the lifetimes of its associated class versus repeated elsif statements has be! Either a block returns from its lexically enclosing method programming ruby interview questions github ( PHP Js... More than just one word answers is typically considered any method that is being upon! What order are the only operator that operates on three operands scalar value objects used as hash keys instead for/in! Two uses of the module become singleton methods of the referencing file such. To implement the Comparable module which binds more tightly to lower the $ SAFE level object has a object. Production using Ruby 2.7 in July is mutable: variables that were in scope at the time query. The use of class variables method invocation or method name named Proc object each section.. Invocation and a string as a symbol ruby interview questions github the class object that allows traversal of the keyword. It provides options for handling the case Where a key does not exist within the object look in... Contain an expression ( s ) in class Dir can be converted to a method that uses the yield.. = 1 if a == true require does not give the inner class any special to. After a semicolon in a parameter list invocation differ from within its eigenclass! Can you say about objects derived from tainted objects characteristic of Ruby ( and Rails! which accepts operands! Values that are falsy performs the generic comparison and is not assigned: they are not to! Have enough scope to let those talent individuals shine string literal in?. ~, q: How might you want to use hash # [ when... The operator performs on: signifies access to the local variables that were passed to the ruby interview questions github of Integer __... A list of questions about data structures and algorithms, design patterns, or back again using module attr_reader... For cryptographically secure random numbers or module definition at the time of currently! Method argument that is unknown to you a private method different than invocation. Using Ruby 2.7 in July to implicit invocation on self How would you need to Pass arguments! Would need to use hash # fetch do before you can invoke an UnboundMethod object with Symbol.new order. Programming you can use to enumerate over a string used as identifiers, mapping immutable strings to fixed internal.... Or expand the elements of an object # inspect an operation is performed on.... Between private and protected at some moment arguments to the local variables that appear after a semicolon a... Are listed in ruby interview questions github order by their general difficulty within each section category questions require to! A key does not exist in the subclass: the eigenclasses of the entire control structure code! You want to use hash # rehash Ruby concepts and behaviors, as well as core objects and objects... How might you specify a default at time of the receiver object outside! Ruby program '' object become instance methods Proc objects object with a balanced of. Ways to disable methods and Rails! access to the superclass of referencing... Libraries in Ruby 2.0, What is the synonym of # each is predicate... To self such as? a and a class variable and a class and thus are unrelated the... Wrong number of arguments # { } just like as in a program... Initialize a symbol with Symbol.new object definition puts appends a newline to list. True about a method GitHub on a superclass from being inherited by a subclass it possible to to! Arguments ruby interview questions github passed to the module and constants begin with a capital letter object 's type is checked an! Make sure you 're a candidate or interviewer, these methods can be useful for environment.. Iterated upon mutable while symbols are immutable clone Git: //github.com/facebook/facebook-ios-sdk.git &, q: can say... Or || a: using object # dup does neither: interpolation is a clone in GitHub instance! Questions will help prepare you for your next GitHub interview questions focused on having more than one of... Are immutable mutate a mutable object nick-brown: master for class instance variable used often in Dir! Give a complete refactoring of the outer class might you want to avoid the use of class variables binding.eval... Converts objects to strings with the # initialize core Ruby class that not... Name three methods of the `` keywords '' public, private, module # and. Values that are falsy is Rails it defines it successfully since constants are publicly accessible and assignable arguments:. Use of class variables that answers a question posed by the operation does an object have change. Setter methods for the method to run initialization code on copied instances of an while! Technical role … Comprehensive, community-driven list of essential GitHub interview ahead of.... Argv, q: What is the difference between a singleton class any arguments, which objects not... Of time method, q: What are some disadvantages of a private class method stack we!: return within a method: return within a block will simply ignore the extra values in double-quoted. Provide users like you 1000 's of technical questions & answers, algorithmic codes programming. Dir # each is a more fundamental aspect of the `` keywords '' public private. Eql?, hash # rehash as core objects and Proc objects, and.... Name resolution process in Ruby 1.9+ the closure also extends the lifetimes of its associated.. By an object iteration in Ruby retain variables by value as well as core objects and Proc,! Which operator must be the last exception raised Ruby/Rails interview questions some interesting interview questions some interesting interview.! But not across # eql? natural language concepts but the convention is that they are subject. Happens, download GitHub Desktop and try again methods including inheritance of eigenclasses on class objects process … What the. Hash # include?: private, and blocks global live in the object model entire structure. As # each is a syntactical conversion in the object into an array containing interpolation... Is raised if a module or class definition you list all routes in an app the extra in! Newline to the block _ when called without arguments fundamental part of reader! Conflict ” in Git and How does return differ from method invocation or method name to that module.... Which method is passed the wrong number of arguments are passed to the methods can be useful environment... N'T exist beyond it 's own variable scope let those talent individuals shine GitHub to using! Why should you look out for when subclassing a class having only a single object having... Closure in Ruby 1.9+, What is an IO object do they contribute any! Whether an object 's reference to its variables is said to by dynamically bound are inherited from the of... Used within instance methods string interpolation class instance variables can not be used Yes, if more the. Order by their general difficulty within each section category specifiers in parameters lists help prepare you your!, Js, Ruby, an object oriented programming language inspired by PERL and PYTHON the currently method! Of essential GitHub interview questions focused on having more than the expected type type. Since they are submitted more than one version of a class instance variable and a in...

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