This means that methods can be called on it. Difference between nil?, empty?, blank? The NilClass class. Checking if a variable is not nil and not zero in ruby; Ruby remove nil values from array with .reject; Remove nil and blank string in an array in Ruby; sorting a ruby array of objects by an attribute that could be nil; ruby - `sort_by': comparison of Array with Array failed (no nil data) Ruby and Rails have several methods that can be used to check for the existence of a value or the state of an object. In Ruby, everything is treated as an object. in validating data as it won’t cause NoMethodErrors when used on some objects since it is available for all objects. Not every object which iterates and returns values knows if if it has any value to return. Goals. Tagged with ruby, rails, beginners. This page was generated for Ruby 2.5.1 Ruby-doc.org is a service of James Britt and Neurogami , an erratic source of art, music, and technology. As a developer mainly working in PHP my first instinct was simply to evaluate the array as a boolean (empty arrays are false-y in PHP). Some of the values we could use can be legitimate values, like: temperature = 0. today_is_friday = false. And blank? If the first part of the conditional is true, Ruby will ignore the next for speed. Well, nil is a special Ruby object used to represent an “empty” or “default” value. As with everything, the choice between #nil?, #empty?, #blank? For example, an_object.try :strip will return nil if an_object is nil, but will proceed otherwise. Developer ruby-on-rails - template - ruby check if nil or empty . It returns false for true and true for any falsey conditions (i.e. When a size and an optional default are sent, an array is created with size copies of default.Take notice that all elements will reference the same object default. Frankly I don’t know why these methods were implemented separately here and why the implementation from, your company’s Slack or other chat - for the benefit of your coworkers, Facebook & Twitter - for fellow developers who you are in touch with. Sign up for our Ruby Magic email series and receive deep insights about garbage collection, memory allocation, concurrency and much more. Ruby is an open-sourced object-oriented programming language developed by Yukihiro Matsumoto.In Ruby, everything is treated as an object. empty? It also won’t pass for strings that only contain whitespace. Ruby provides #nil? def is_nil_or_empty? Collect metrics and visualize them with a few lines of code. How to find records where column is not null or empty in Rails 4 or 5 We all know that especially in legacy applications sometimes our database columns are not that well maintained. # For example, +false+, '', ' ', +nil+, [], and {} are all blank. So we need to query for, or exclude rows containing nil/NULL and empty strings ("") as well. Provided by Ruby; Can an be used on anything; Will return true Perhaps for speed of not checking if they have empty? blank? Mostly just for shits and giggles, and because I was currious about the core implementations of these methods They are available on all objects, work intuitively well (by following the principle of least surprise) and you don’t need to manually check for nil anymore. nil.to_s => "", so you can say thing.to_s == "" – DigitalRoss Jan 11 '11 at 1:39 1 @DigitalRoss This avoids the string conversion which may or may not be a slight performance issue. Difference between .nil?, .empty?, .blank?, .present? In this guide, I wanted to put together a … for # false It can also be using on Strings (because you can think of String as a collection of bytes/characters) 1. It turns out there are many ways to skin this cat. The documentation says blank? and blank?checks if the array representation of the relation is blank. When a size and an optional default are sent, an array is created with size copies of default.Take notice that all elements will reference the same object default. can be used on any object. Course, Ruby job offers at our Step 1. Ruby methods can seem pretty daunting to a new programmer and knowing when to use which one can feel like a giant black hole. Ruby check if nil before calling method (6) ActiveSupport comes with a method for that : try. Ruby provides #nil? rails ķ .nil? is a String class method in Ruby which is used to check whether the string length is zero or not. choice This article is an English version of an article which is originally in the Chinese language on aliyun.com and is provided for information purposes only. arr #=> [1, 2, 's', '', 'd'] doesn't remove empty string. If you liked this explanation please consider sharing this link on: Now, a plug . .empty? For the case of empty, # strings we can speed up this method (~3.5x) with an empty? This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. is a String class method in Ruby which is used to check whether the string length is zero or not. All these work in their own way and it’s important to know how each evaluates data as using the wrong method in your code might cause unexpected results. nil? and #empty?, and Rails’ ActiveSupport adds #blank?#nil? That's not very informative, so let's have a look at the code of the methods. is also a Rails method. #empty? In the first form, if no arguments are sent, the new array will be empty. and #empty?, and Rails’ ActiveSupport adds #blank? And present? # penalty for the rest of strings is marginal. Skip to content. depends on the situation. If whatever function is returning this data can return an "empty" value, it should be returning nil, not "". Here I’ll document my learnings… Evaluating The Array As A Boolean. è un metodo standard di Ruby che può essere chiamato su tutti gli oggetti e restituisce true se l'oggetto è nil: b = nil b.nil? in Ruby on Rails, nil? It turns out there are many ways to skin this cat. The. [ "", " ", false, nil, [], {} ].all?(&:blank?) I'm trying to ... Ruby on Rails: First argument in form cannot contain nil or be empty. If you are only using this method to validate user input, for instance, you might end up processing input that only contains whitespace. пյġ .nil? The second form creates a copy of the array passed as a parameter (the array is generated by calling #to_ary on the parameter). Note that whitespace characters are characters and so using #empty? For many beginning Rubyists, especially those having experience in other programming languages such as Java or C, checking whether variable is nil may seem a little bit confusing. This article is an English version of an article which is originally in the Chinese language on aliyun.com and is provided for information purposes only. Let’s see how. Provided by Ruby; Can an be used on anything; Will return true Perhaps for speed of not checking if they have empty? So value.nil? and present? ж϶ Ƿ ڣ nil ڵĶ nil .empty? The opposite of blank? Ruby One Method Ruby, Returns: It returns true if str has a length of zero, otherwise false. When used on strings, it returns true for empty strings. There are plenty of options available. # => true b = ["2","4"] b.empty? empty? 1. If you do too, let us know. in Ruby and , empty? in Ruby on Rails, nil? Difference between nil?, empty?, blank? ruby-on-rails,ruby,ruby-on-rails-4,ruby-on-rails-3.2. #nil? but it is not included in Enumerable. Since all classes inherit from this class, #nil? static VALUE false_or(VALUE obj, VALUE obj2) { return RTEST(obj2)?Qtrue:Qfalse; } This page was generated for Ruby 2.7.0 on a string containing only whitespace will return false. Ruby empty string. Why are you writing this. does. It operates on any object. and #empty?, and Rails’ ActiveSupport adds #blank? è un metodo standard rubino che può essere richiamato su alcuni oggetti come corde, array e hash e restituisce true se questi oggetti contengono alcun elemento: a = [] a.empty? Ruby nil check. end. is a method that can be used on strings, arrays, hashes and sets. This is convenient for web applications because you often want to reject or handle differently string which contain only invisible spaces. It’s equivalent to null or None in other programming languages. #nil? Controllers, Responsible Rails: Whenever Ruby requires a Boolean value, then nil behaves like false and values other than nil or false behave like true. and .empty?, .blank? empty? How to find records where column is not null or empty in Rails 4 or 5 We all know that especially in legacy applications sometimes our database columns are not that well maintained. You can also convert the value to string before checking empty, so that you don’t wanna always follow this order. I have been puzzled or confused with the method nil?, empty?, blank? on the Object class, but this is overridden by more … Arkency blog, Painless search pages in We’ll even throw in a handy cheat sheet at the end! returns truefor relations with no records. # => true b = ["2","4"] b.empty? # => true # present? # An object is present if it's not blank. There are a number of different approaches to this problem, and I … If you have any questions or comments, don’t hesitate to drop us a line @AppSignal. But, they are not just empty value or simple keywords, just like with everything else, both true and false are Ruby objects. Returns a new array. ruby ķ .blank? method it will effortlessly work as well. Each of these keywords evaluates to an object that is the sole instance of its respective class. nil? objects are instances of NilClass. For arrays, hashes and sets, it returns true if they have no elements. Ruby, Returns: It returns true if str has a length of zero, otherwise false. One of the things I love about Ruby is nil. As everything in Ruby is object, the nil value refers to the non-instantiable NilClass class. empty? Ruby Method: Def, Arguments and Return Values Review the syntax of methods: receive parameters and return values with methods. nil - ruby if not empty . Ruby provides #nil? - is just a double negation of empty?. end. Unlike .nil? So value.nil? ൱ ͬʱ .nil? nil and void difference between nil and nill difference between nil and null difference between isset and empty in php switch and case in c mysql select switch sql select switch Related Article Ruby on Rails Primer Example (Ruby1.8.6 gem 1.3.1 Rail 2.2.3) 07-23 empty? is used on nil or any other class that doesn’t have the method, a NoMethodError exception will be raised. Provided by Rails. To check for the empty string, array, hash. Ruby empty string. Find performance issues before they find you. That means that if a relation hasn't been preloaded yet then it loads all its records. and #present return a boolean for all objects, which might hide bugs in the code by not raising an error when a value is of the wrong type. What about introducing NilClass#empty?. How to test if parameters exist in rails (10) I'm using an IF statement in Ruby on Rails to try and test if request parameters are set. I'm looking for a more idiomatic way to filter out nil-or-empty elements of an array. (Careful of this if you use a function as a conditional and rely on it being run regardless of the outcome) You could probably do: If(params[:category_id] “”).empty If params[:category_id] is nil, the evaluation of the parens will be “”. is implemented completely in ruby. – meagar ♦ Apr 13 '13 at 15:36 is an ActiveSupport extension to Ruby Object and returns true for nil, false, empty, or a white-space string. and #empty?, and Rails’ ActiveSupport adds #blank? まず、nil?とempty?はrubyのメソッドで、blank?とpresent?はrailsで拡張されたメソッド(つまりrubyでは使えない)ってことを覚えておく。-nilは存在しないという意味。 対して ""は「何も無い」が存在している。空白の存在。 When #empty? # => true empty? ˵ Returns true when they have no elements. Viewed 24 times 0. empty_phrase = "" Nil to the rescue. in Ruby on Rails. Trustworthy Rubyʼs raise Exception.new or raise Exception — they're both the same, OOP Refactoring: from a god class to smaller objects, Domain-Driven Rails I have many methods of the form: def joined [some_method, some_other_method].compact.reject(&:empty? 1. but it is not included in Enumerable. - nil_empty_blank_present_ffdierence_in_ruby. I love Ruby on rails.Ruby on Rails Coding is not my job its my passion .. Syntax: str.empty? A better method to use would be the Rails #blank? and empty? Nil in Ruby ?, Empty? is a Ruby method on the Object class. !!empty? will return true and ruby won’t check the second part since ruby uses Short Circuit Evaluation. and empty? This post is written by guest author Joyce Echessa. Active yesterday. How do you set a variable to empty? method which Ruby 2.3.0 added a safe navigation operator (&.) nil is a special Ruby data type that means “nothing”. How do you do it differently? will return true and ruby won’t check the second part since ruby uses Short Circuit Evaluation. React.js course, Fearless Refactoring: Rails However #blank? As a developer mainly working in PHP my first instinct was simply to evaluate the array as a boolean (empty arrays are false-y in PHP). end. if test() == nil puts true end Output true. In the first form, if no arguments are sent, the new array will be empty. true, false and nil are built-in data types of Ruby.. A boolean It does the opposite of what #blank? # false You can also pass a block to this method: [1,2,3].any? in Ruby and , empty? In this article, we’ll refresh your knowledge on these methods. Or—Returns false if obj is nil or false; true otherwise. objects are false, empty, or a whitespace string. Generated with Ruby-doc Rdoc Generator 0.44.0 . This is where presence comes in handy. We are located in beautiful Amsterdam. Ben As for empty?, its behaviour varies depending on if the relation has been loaded and may generate a database query to count relation records and return its result. nil? empty? ruby-on-rails - present - ruby check if nil or empty . NilClass is a built-in class provided by Ruby. Returns a new array. empty? For arrays, hashes and sets, it works just like #empty?, in that it returns true if they have no elements. def is_nil_or_empty? # => true. nil? are just contents checks with slightly different focuses. value value. Generated with Ruby-doc Rdoc Generator 0.44.0 . At their base level the ruby methods nil? empty? But I thought it would be interesting and maybe even useful to look at how each actually opperates. Ask Question Asked yesterday. Why are you writing this. # => true empty? Every expression and every object in Ruby has a boolean value, which means that every object and every expression must either evaluate to true or to false. Ruby and Rails have several methods that can be used to check for the existence of a value or the state of an object. If the original proposal is going to be realized, then a new method would have to be added to NilClass, String, Array, and Hash, but my proposal makes use of the existing method empty?, and needs to add to only NilClass, keeping the change minimal. Ruby check if nil before calling method (6) ActiveSupport comes with a method for that : try. nil?, empty?, blank? Example: [nil].any? and #present?. This page was generated for Ruby 2.5.1 Ruby-doc.org is a service of James Britt and Neurogami , an erratic source of art, music, and technology. Sometimes you would like to write a logic such as: but because the parameters can come from forms, they might be empty (or whitespaced) strings and in such case you could get '' as a result instead of 'US'. nil? As you can see, it is better to use #blank? is a standard Ruby method on some objects like Arrays, Hashes and Strings. is also an ActiveSupport extension to Ruby Object and it is the negation of blank? empty? There are all somewhat related since all of them check for the absence of data in some way. Let’s say I have an array like this: arr = [1, 2, 's', nil, '', 'd'] and I want to remove nil and blank string from it, i.e. true.class => TrueClass false.class => FalseClass nil.class => NilClasstrue and false are Ruby’s native boolean values. railsAPI еĽ ǣ false,empty, հ ַ . and present? Not every object which iterates and returns values knows if if it has any value to return 1. We hope we refreshed your memory on checking values in Ruby. || value. and #present?.All these work in their own way and it’s important to know how each evaluates data as using the wrong method in your code might cause unexpected results. Ask Question Asked 8 years ago. The code in question can be written simply as: unless ary. For example, "", " ", nil, [], and {} are blank. and present? Ruby on Rails: Using default value, when the variable is null or empty (2) I have this code-snippet in html erb. method, which we’ll now look at. that checks for nil before calling a method. Provided by Ruby 2. AppSignal keeps your team focused on building great apps. can be used on some Ruby objects including Arrays, Hashes and Strings . value value. If you are working in Rails I recommend using present? It’s helped me identify errors quickly and has provided some great insight on performance.". But I thought it would be interesting and maybe even useful to look at how each actually opperates. The problem with empty? This is useful in case empty? Catch errors and make sure they don't happen again. Let’s evaluate their usefulness and potential problems that they bring to the table. empty?gli oggetti sono specifici della classe e la definizione varia da classe a classe. This makes true and false rather special values. returned nil or a string or a number, something different than true or false. objects are class-specific, and the definition varies from class to class. Programmers, It can also be using on Strings (because you can think of String as a collection of bytes/characters), The logic for every other class is that if it implements, No number or Time is blank. empty? is a Ruby method on the Object class. Can be used on collections such as Array, Hash, Set etc. Course, Junior Rails It can represent nothing and, since every expression in Ruby has a return value, nil is also a useful proxy for certain behavior. #present? At their base level the ruby methods nil? I am new to Ruby and stuck with this issue. Ruby and Rails have several methods that can be used to check for the existence of a value or the state of an object. Every expression and every object in Ruby has a boolean value, which means that every object and every expression must either evaluate to true or to false. Join ARKADEMY.DEV and get access to our best courses: Rails Architect Masterclass, Anti-IF course, Blogging for busy programmers, Async Remote, TDD video class, Domain-Driven Rails video course and growing! in Ruby and Ruby on Rasils. final array should be: arr = [1, 2, 's', 'd'] I tried compact but it gives this: arr.compact! Clearly, these … Its exact behaviour will depend on the specific object, but typically it … nil? # some code end. #blank? So we need to query for, or exclude rows containing nil/NULL and empty … is that you need t… to_s. For some objects the cover_image_url is empty, how do i modify this code block to use a default value ,when that property is null or empty? This makes true and false rather special values. end. 1. The second form creates a copy of the array passed as a parameter (the array is generated by calling #to_ary on the parameter). # => false Viewed 9k times 19. could be a good fit, for example. Know what nil is for. Here you can learn more about enumerators 1. I find myself repeatedly looking for a clear definition of the differences of nil?, blank?, and empty? Here I’ll document my learnings… Evaluating The Array As A Boolean. Parameters: Here, str is the given string which is to be checked. def test end # Test return value of method. It's equivalent to null or None in other programming languages. è un metodo standard di Ruby che può essere chiamato su alcuni oggetti come Stringhe, Array e Hash e restituisce true se questi oggetti non contengono alcun elemento: a = [] a.empty? Joyce is a full stack developer. Since the naming of these methods tends to confuse, here’s a handy cheat sheet for you to bookmark. For checking if a user has a name to address them with, #present? It returns true for nil (an instance of the class NilClass) and false for everything else. Note: Always remember in Ruby true, false, and nil are objects, not numbers.Whenever Ruby requires a Boolean value, then nil behaves like false and values other than nil or false behave like true. Ruby:nil, empty? Ruby program that uses empty method, nil # This empty method returns nil. .empty? The options Ruby offers come in the form of several methods: “present?”, “blank?”, “nil?”, and “empty?”. Ѿ ڣ ж Ƿ Ϊ ֶΣ һ ַ Ƿ Ϊ մ һ Ƿ ֵ е жϳ Ƿ Ϊ 㣬 Ǻ .blank? static VALUE false_or(VALUE obj, VALUE obj2) { return RTEST(obj2)?Qtrue:Qfalse; } This page was generated for Ruby 2.7.0 How can we do it in ActiveRecord? This class is not instantiable. nil. Because of this, it might not be the best method to use when validating text. Tags: Ruby My eBook: “Memoirs of a Software Team Leader” Read more. nil and false). The "Ruby way" would be to not get into a state where you have a mixture of nils and empty strings. static VALUE false_or(VALUE obj, VALUE obj2) { return RTEST(obj2)?Qtrue:Qfalse; } This page was generated for Ruby 2.6 nil - ruby if not empty . empty? For example, nil can… Ruby nil check. and #present? and/or blank?. # blank? can be used on some Ruby objects including Arrays, Hashes and Strings . def is_nil_or_empty? static VALUE false_or(VALUE obj, VALUE obj2) { return RTEST(obj2)?Qtrue:Qfalse; } This page was generated for Ruby 2.6 Node.js Garbage Collection: Heap Statistics Magic Dashboard, How Absinthe Uses Compilation Callbacks for Schema Validation in Elixir, How to Use Mixins and Modules in Your Ruby on Rails Application, Microservices Monitoring: Using Namespaces for Data Structuring, Top 5 Ruby Blog Posts in 2020 from AppSignal, Top 5 Elixir Blog Posts in 2020 from AppSignal, Top 5 JavaScript Blog Posts in 2020 from AppSignal, New Magic Dashboard for Ruby on Rails: ActionMailer, Setting Up AppSignal Monitoring for a Ruby on Rails Application, The Easiest Way to Monitor Node.js: Automatic Instrumentation. Mi ritrovo a volte alla ricerca di una definizione chiara delle differenze di nil?, blank?e empty?in Ruby on Rails.Ecco il più vicino che sono venuto: blank?gli oggetti sono falsi, vuoti o una stringa di spazi bianchi.Ad esempio, "", " ", nil, [], e {}sono vuoti. It returns true if the instance of the object has a length of zero. Since all classes inherit from this class, #nil? It’s also a “falsy” value, meaning that it behaves like false when used in a conditional statement. The options Ruby offers come in the form of several methods: “present?”, “blank?”, “nil?”, and “empty?”. All gists Back to GitHub Sign in Sign up Sign in Sign up {{ message }} Instantly share code, notes, and snippets. We can speed up this method ( ~3.5x ) with an empty string this guide, I was on. Will proceed otherwise ll get false, empty?, and nil are built-in data types of,. ֶΣ һ ַ Ƿ Ϊ ֶΣ һ ַ Ƿ Ϊ 㣬 Ǻ.blank?, and ’! |N| n > 0 } # true this will check if n > 0 } # true will. Is convenient for web applications because you can also convert the value to string before empty! A length of zero, otherwise false be raised Ruby ; can an be used on ;... Can feel like a giant black hole because you often want to reject or handle differently string which contain invisible! No arguments are sent, the choice between # nil?, and { } ].all (... To an object that is also a little bit wrong NilClass ) cheat for. About introducing NilClass # empty?, and I … What about introducing NilClass # empty?, {! Code in question can be called on it out nil-or-empty elements of an.... Where I had to check the object has a name to address them with a method for validation than empty... It turns out there are many ways to skin this cat the!... Is present if it 's false, empty? gli oggetti sono della! Function is returning this data can return an `` empty '' value, meaning that behaves... String class method in Ruby, returns: it returns true if they have no elements, and { ]. - is just a double negation of empty, հ ַ you ’ ll get,. At how each actually opperates as it won ’ t cause NoMethodErrors when used nil... Hope we refreshed your memory on checking values in Ruby, Rails, Elixir, Phoenix,,... Throw in a handy cheat sheet at the end all classes inherit this. First part of the values we could use can be used on some objects since it is better use. The method, a plug template - Ruby check if n > 0 is for... You to bookmark concurrency and much more block to this method ( ). Will proceed otherwise pass for strings, it is available for checking the of. Strings as well ve come: blank? to look at the end it in checking your data, have... An instance of the values we could use can be called on it we covered for #?... Ruby ; can an be used on some objects since it is available for checking if a has... Everything is treated as an object is present if it 's not very informative, so you... ``, 'd ' ] does n't remove empty string is not a nil though, so this is by... Trying to implement search feature on Rails: first argument in form can not nil... The state of an object is present if it has any value to return white-space. ) and false are Ruby ’ s also a better method for that: try no elements it. 'M looking for a more idiomatic way to filter out nil-or-empty elements of an array is not my its... It loads all its records strip will return true and Ruby won ’ t hesitate to drop us a @! Great insight on performance. `` comments, don ’ t hesitate drop. On building great apps to implement search feature on Rails: first in. 'S ', ``, 'd ' ] does n't remove empty string, array,.! Trying to... Ruby on Rails: first argument in form can not contain nil any... An ruby nil or empty жϳ Ƿ Ϊ 㣬 Ǻ.blank?, blank? #?! Programmer and knowing when to use ruby nil or empty in checking your data, you to. Present - Ruby check if nil before calling method ( 6 ) ActiveSupport comes with a few of. Will be empty ” when trying to implement search feature on Rails Coding is a. This will check if n > 0 is true for empty ruby nil or empty well! Happen again not contain nil or a number of different approaches to this method ( )! Nil.Class = > TrueClass false.class = > TrueClass false.class = > true b = [ `` 2 '' ''. Activesupport extensions and defines blank? checks if the instance of the class NilClass ) and for! Don ’ t cause NoMethodErrors when used on strings, Arrays, Hashes and sets ( &: empty,. Here, str is the sole instance of the object class, # strings we can speed up this:. Its my passion since all of them check for different types of Ruby here ’ s helped me errors! This problem, and Rails ’ ActiveSupport adds # blank? present if it any. Ll get false, and Rails ’ ActiveSupport adds # blank? checks if the instance of relation. A mixture of nils and empty strings as well as strings containing only whitespace characters are characters so., there are a number, something different than true or false informative, so let have... A Boolean if test ( ) == nil puts true end Output true is true for falsey... Of the class NilClass ) and false for everything else case of empty, or a string. This article, we ’ ll Now look at validating data as it ’! Objects are false, empty?, empty? the things I love Ruby. Ruby will ignore the next for speed of not checking if they have empty.... For at LEAST one element s evaluate their usefulness and potential problems they. Relation has n't been preloaded yet then it loads all its records Ruby my eBook: “ Memoirs a! Returning this data can return an `` empty '' value, meaning that it behaves like false when in. Only non-truthy ( nil/false ) values you ’ ll document my learnings… Evaluating the as! String or a whitespace string a method for that: try related since all of them for... Method returns nil method in Ruby, nil in an object let 's have a of. Example 1: an empty?, empty, # present Ƿ ֵ е жϳ Ƿ Ϊ ֶΣ һ Ƿ! 'S not very informative, so that you don ’ t pass for strings that only contain.! For all objects { |n| n > 0 } # true this will check if an array is not empty. Anything ; will return true and Ruby won ’ t check the part. Receive deep insights about garbage collection, memory allocation, concurrency and much more # for,! ] b.empty Ruby ruby nil or empty Rails: first argument in form can not nil! The rest of strings is marginal joined [ some_method, some_other_method ].compact.reject ( &. feature... “ falsy ” value, meaning that it behaves like false and values other nil. Ebook: “ Memoirs of a value or the state of an object that is the instance! Return false written by guest author Joyce Echessa place more checks to ensure your program never crashes `` way! Not every object which iterates and returns values knows if if it has any value to string before empty... White-Space string returned nil or empty has n't been preloaded yet then it loads all its records,. Template - Ruby check if nil or a string containing only whitespace characters this link on Now. 1, 2, 's ', +nil+, [ ], and Rails have methods... Don ’ t wan na always follow this order is the given string which used! Are all somewhat related since all classes inherit from this class, # nil?, empty? as containing! Questions or comments, don ’ t wan na always follow this.! The Rails # blank? None in other programming languages 'm trying implement. Is convenient for web applications because you can also convert the value to string checking. They check for the existence of a value or the state of an.! The string length is zero or not some of the class NilClass ) for strings that only contain.... And nil are objects, not numbers for, or exclude rows containing and! For any falsey conditions ( i.e or the state of an object turns... This is convenient for web applications because you often want to reject or handle string! Containing nil/NULL and empty strings n't been preloaded yet then it loads all its records just a double negation empty. That way the returned value is always converted to a Boolean value adds # blank? # nil? and... Na always follow this order idiomatic way to filter out nil-or-empty elements of an object is blank if has. It 's not very informative, so that you don ’ t wan na always follow order. Uses Short Circuit Evaluation for, or a white-space string for, or a string! Short Circuit Evaluation s native Boolean values ruby nil or empty even throw in a handy cheat sheet at code. And so using # empty?, blank? # nil?,?! With an empty?, blank? the Rails # blank? extensions and blank... Ll Now look at how each actually opperates to string before checking empty, #?., meaning that it behaves like false and values other than nil or be empty includes... Out nil-or-empty elements of an object is blank these … in Ruby,... You have any questions or comments, don ’ t check the second part since Ruby uses Short Circuit.!