Find Complete and recently updated Correct Question and answers of Clojure. All Answers updated regularly with new questions. Upwork Clojure test answers of 2016.

Question:* What is Clojure a dialect of?

Answer: • Lisp

Question:* True or False? Clojure is NOT an imperative language.

Answer: • True

Question:* Vars _____

Answer: • provide thread-local variable bindings

Question:* In many object-oriented languages, ________________ is a way to decouple a class from other objects upon which that class depends.

Answer: • dependency injection

Question:* True or False? Metadata is data about data, and has no effect on the 'host' data.

Answer: • True

Question:* ________ evaluates all of the expressions provided to it in order and yields the last expression's value as its value.

Answer: • do

Question:* True or False? Clojure a functional language.

Answer: • True

Question:* What is the syntax of the "if" function?

Answer: • (if condition then-expr else-expr)

Question:* Which is an example of a Clojure function call?

Answer: • (function-name arg1 arg2 arg3)

Question:* Which of the following Clojure fragments calculates (4+2)*(5-3)?

Answer: • (* (+ 4 2) (- 5 3))

Question:* What is significant about function names that end with a "!"?

Answer: • It is a convention that indicates the function mutates some state.

Question:* A function can be stored in a var or passed as an argument to other functions.

Answer: • True

Question:* In Clojure, you can create a new class using _____

Answer: • All of the above

Question:* Clojure strings are Java Strings and are represented in exactly the same way, delimited by double quotes.

Answer: • True

Question:* Which is a type of collection in Clojure?

Answer: • All of these

Question:* True or False? Sets are collections of unique items. They are better than lists and vectors when duplicates aren't allowed.

Answer: • True

Question:* Which statement best describes protocols in Clojure?

Answer: • A protocol defines an interface. But unlike Java interfaces, which must be specified when a class is created, protocols can be attached to a class at any time.

Question:* What is the function that evaluates a single argument form?

Answer: • eval

Question:* True or False? Arity is the number of arguments a function can handle.

Answer: • True

Question:* Leiningen uses _____ to locate and manage project dependencies

Answer: • Maven

Question:* Clojure documentation can be accessed

Answer: • All of the above

Question:* What does the REPL tool do?

Answer: • Read-eval-print loop

Question:* Which of the following code fragments evaluates to 5?

Answer: • All of the above

Question:* Clojure is hosted on the JVM (Java Virtual Machine) and can use any Java library.

Answer: • True

Question:* True or False? In Clojure a symbol can contain characters that most imperative languages don't allow in variable names. (Example: in Clojure you can have a symbol with the name +a-.)

Answer: • True

Question:* What does the "contains?" function work on?

Answer: • All of these

Question:* Does Clojure have a metadata system that allows for annotation of symbols and collections?

Answer: • True

Question:* True or False? Clojure programs only support some Java classes and interfaces.

Answer: • False

Question:* To calculate the average of some numbers in Clojure, your code would look like this:

Answer: • (defn average [numbers] (/ (apply + numbers) (count numbers)))

Question:* True or False? The Clojure language is homoiconic.

Answer: • True

Question:* Collections that classically support last-in, first-out (LIFO) semantics are called ____________.

Answer: • stacks

Question:* What type does the following code result in? {:a 1 "b" 2}

Answer: • Map

Question:* Which statement about Clojure macros is true?

Answer: • Macros allow programmers to specify program transformations that occur during compile time.

Question:* The reduce function is used to _____

Answer: • aggregate the elements in a collection using a given function and return the result as a single value

Question:* lib-noir, Ring, and Compojure are all examples of Clojure:

Answer: • HTTP service modules

Question:* How do you create an anonymous function?

Answer: • #(single-expression)

Question:* :foo is an example of a(n) _____

Answer: • keyword

Question:* How do you add metadata to a symbol or collection?

Answer: • ^{key-value-pairs} object

Question:* What are sequences?

Answer: • Logical views of collections

Question:* What do keywords begin with?

Answer: • :

Question:* The following code will evaluate to true? (defn +++ [n] (+ (inc n) 1)) (= (+++ 1) 3)

Answer: • True

Question:* The two comment types that are defined by the reader are:

Answer: • Single-line comments and Form-level comments

Question:* REPL stands for _____

Answer: • Read, Eval, Print, Loop

Question:* If you are already using Java or another JVM language for RDBMS work, it’s likely that you’re using ______________, easily the most popular Java object/ relational mapping library.

Answer: • Hibernate

Question:* The map function is used to _____

Answer: • apply a function to all elements in a collection and return a sequence of the results

Question:* A built-in Clojure "operation" may be implemented as a...

Answer: • All of these

Question:* STM stands for _____

Answer: • Software Transactional Memory

Question:* Stack abstraction is supported in Clojure via what three operations?

Answer: • conj, pop, peek

Question:* What are the 3 phases Clojure code is processed in?

Answer: • Read-time, compile-time, run-time

Question:* Clojure provides several "persistent" data structures. Objects of these classes are _____

Answer: • immutable

Question:* Clojure is primarily an imperative language.

Answer: • False

Question:* How would you want to create a new Atom with an initial value <value>?

Answer: • (atom <value>)

Question:* What type does the following code result in? [1 2 3 4]

Answer: • Vector

Question:* A(n) ________ is a named Emacs object that represents something editable, usually a file in your filesystem, but also the Clojure REPL or debugger, for example.

Answer: • Buffer

Question:* What is the literal syntax for maps?

Answer: • {:a 1 :b 2}

Question:* True or False? A lazy-sequence can hold all the possible calculations of the Fibonacci sequence.

Answer: • True

Question:* A multimethod is created using a form, and implementations of a multimethod are provided by ___ form.

Answer: • defmulti, defmethod

Question:* We can use _____________ to create a table with a specific name and define columns.

Answer: • create-table

Question:* Which statement about -> and comp is true?

Answer: • -> is a macro while comp is a higher order function

Question:* What is generally the first step in deploying your Clojure web application?

Answer: • Installing and configuring Leiningen or setting up and configuring an app server.

Question:* What is the conventional first and last character used to name vars intended to be bound to new, thread-local values?

Answer: • *

Question:* What's a difference between quote (') and syntax-quote (`) macro characters?

Answer: • Syntax-quote (`) fully qualifies symbols, while quote (') doesn't

Question:* (= (map + '(1 2 3)) 3)

Answer: • False

Question:* True or False? Function definitions must appear before they're first used.

Answer: • True

Question:* Which statement regarding Clojure "forms" is true?

Answer: • Every function call is a form, but not every form is a function call.

Question:* ________ is a very low-level looping and recursion operation that is usually not necessary.

Answer: • recur

Question:* Locks _____

Answer: • are a low-level construct that should be avoided in most cases

Question:* In Clojure >= 1.3, which of these follows the naming conventions for dynamic objects? (def ^:dynamic d (atom [])) (def ^:dynamic d (atom []))

Answer: • d, but not d

Question:* To represent a boxed decimal in Clojure, you would use ____________.

Answer: • java.lang.Double

Question:* To represent a boxed decimal in Clojure, you would use ____________.

Answer: • java.lang.Double

Question:* In Clojure, tail-call optimization is _____

Answer: • not supported natively by the compiler, but could be simulated using thunks, trampolines, and macros.

Question:* You can use ___________ whenever you like if you need a unique symbol, but its primary role is in helping us write hygienic macros.

Answer: • gensym

Question:* For the following code to evaluate without error, what needs to be added? (def regex "<a>(.*)</a>") (re-seq regex "<a>Ryan Kelker</a>")

Answer: • # symbol before the string in regex

Question:* let is a _____

Answer: • Special Form

Question:* Suppose you want to implement a set of mutually-recursive functions. Which approach might you take?

Answer: • Define the functions using letfn

Question:* True or False? (reset!) is used to set the value of an atom.

Answer: • True

Question:* Agents _____

Answer: • manage independent, asynchronous changes to a single location

Question:* What provides synchronous changes to a single piece of shared data?

Answer: • Atoms

Question:* What provides synchronous changes to a single, thread-local value?

Answer: • Var

Question:* True or False? In functional oriented languages, you can't manipulate objects like in object oriented languages.

Answer: • False

Question:* (.split "Java String" " ") returns

Answer: • A Java array of strings

Question:* If you want to create class that extends another class, you must use _____

Answer: • gen-class

Question:* The application of advice or other aspect transformations is often called __________.

Answer: • weaving

Question:* A "dynamic" var _____

Answer: • has a value that is related to the call stack, and can be used to pass contextual information between functions that do not call each other directly

Question:* Atoms _____

Answer: • manage independent, synchronous changes to a single location

Question:* A _______ is a construct that suspends some body of code, evaluating it upon demand, when it is "deref"erenced.

Answer: • delay

Question:* Refs _____

Answer: • provide thread-isolated transactions

Question:* The Clojure reader can be extended using _____

Answer: • tagged literals

Question:* What is the Closure equivalent to ClassName.class in Java?

Answer: • ClassName

Question:* What's the value returned by... (let [[x y [z]] [2 4 [8 9]]] (list x y z))

Wednesday, December 16, 2015

Clojure test answers of 2016.

Question:* What is Clojure a dialect of?

Answer: • Lisp

Question:* True or False? Clojure is NOT an imperative language.

Answer: • True

Question:* Vars _____

Answer: • provide thread-local variable bindings

Question:* In many object-oriented languages, ________________ is a way to decouple a class from other objects upon which that class depends.

Answer: • dependency injection

Question:* True or False? Metadata is data about data, and has no effect on the 'host' data.

Answer: • True

Question:* ________ evaluates all of the expressions provided to it in order and yields the last expression's value as its value.

Answer: • do

Question:* True or False? Clojure a functional language.

Answer: • True

Question:* What is the syntax of the "if" function?

Answer: • (if condition then-expr else-expr)

Question:* Which is an example of a Clojure function call?

Answer: • (function-name arg1 arg2 arg3)

Question:* Which of the following Clojure fragments calculates (4+2)*(5-3)?

Answer: • (* (+ 4 2) (- 5 3))

Question:* What is significant about function names that end with a "!"?

Answer: • It is a convention that indicates the function mutates some state.

Question:* A function can be stored in a var or passed as an argument to other functions.

Answer: • True

Question:* In Clojure, you can create a new class using _____

Answer: • All of the above

Question:* Clojure strings are Java Strings and are represented in exactly the same way, delimited by double quotes.

Answer: • True

Question:* Which is a type of collection in Clojure?

Answer: • All of these

Question:* True or False? Sets are collections of unique items. They are better than lists and vectors when duplicates aren't allowed.

Answer: • True

Question:* Which statement best describes protocols in Clojure?

Answer: • A protocol defines an interface. But unlike Java interfaces, which must be specified when a class is created, protocols can be attached to a class at any time.

Question:* What is the function that evaluates a single argument form?

Answer: • eval

Question:* True or False? Arity is the number of arguments a function can handle.

Answer: • True

Question:* Leiningen uses _____ to locate and manage project dependencies

Answer: • Maven

Question:* Clojure documentation can be accessed

Answer: • All of the above

Question:* What does the REPL tool do?

Answer: • Read-eval-print loop

Question:* Which of the following code fragments evaluates to 5?

Answer: • All of the above

Question:* Clojure is hosted on the JVM (Java Virtual Machine) and can use any Java library.

Answer: • True

Question:* True or False? In Clojure a symbol can contain characters that most imperative languages don't allow in variable names. (Example: in Clojure you can have a symbol with the name +a-.)

Answer: • True

Question:* What does the "contains?" function work on?

Answer: • All of these

Question:* Does Clojure have a metadata system that allows for annotation of symbols and collections?

Answer: • True

Question:* True or False? Clojure programs only support some Java classes and interfaces.

Answer: • False

Question:* To calculate the average of some numbers in Clojure, your code would look like this:

Answer: • (defn average [numbers] (/ (apply + numbers) (count numbers)))

Question:* True or False? The Clojure language is homoiconic.

Answer: • True

Question:* Collections that classically support last-in, first-out (LIFO) semantics are called ____________.

Answer: • stacks

Question:* What type does the following code result in? {:a 1 "b" 2}

Answer: • Map

Question:* Which statement about Clojure macros is true?

Answer: • Macros allow programmers to specify program transformations that occur during compile time.

Question:* The reduce function is used to _____

Answer: • aggregate the elements in a collection using a given function and return the result as a single value

Question:* lib-noir, Ring, and Compojure are all examples of Clojure:

Answer: • HTTP service modules

Question:* How do you create an anonymous function?

Answer: • #(single-expression)

Question:* :foo is an example of a(n) _____

Answer: • keyword

Question:* How do you add metadata to a symbol or collection?

Answer: • ^{key-value-pairs} object

Question:* What are sequences?

Answer: • Logical views of collections

Question:* A multimethod is created using a form, and implementations of a multimethod are provided by ___ form.

Question:* In Clojure >= 1.3, which of these follows the naming conventions for dynamic objects? (def ^:dynamic d (atom [])) (def ^:dynamic d (atom []))

Answer: • d, but not d