Intro to Clojure (L15) Flashcards
Clojure is designed as a modern dialect of what other language?
LISP
Clojure is implemented on top of what virtual machine?
The Java Virtual Machine.
Does Clojure have direct support for concurrency?
Yes.
Clojure expressions are written in parenthesis, and are also called?
Forms.
In Clojure, basic math operations use infix notation.
False, they use prefix notation (as all Clojure functions do).
Clojure forms may be void, in that they return nothing.
False, Clojure expressions always return something.
What is the name of Clojure’s command line interface, and what does it stand for?
REPL stands for READ-EVAL-PRINT-LOOP.
What character is used to comment in Clojure?
The semi colon (;).
What value is returned by Clojure’s print & println forms?
nil
What are Clojure’s 5 primitive types?
Integer, float, string, boolean, and nil.
Types are explicitly defined in Clojure.
False.
Are Clojure’s boolean literals written in capitalized form, or all lowercase?
All lowercase.
Are strings enclosed by single or double quotes in Clojure?
Double.
Labels associated to values using the “def” function can be reassigned later.
They can be, but aren’t meant to be changed.
Does the label, or the value come first following a call to “def”?
Label, then value.
What is the difference between fn and defn in Clojure?
fn defines an anonymous function that may then be labelled using def. defn combines def and fn into one operation.
How are values returned by functions in Clojure?
The value to be returned must be the final form in the function body.
When using REPL, what will the following line output?
(fn [] “hello world”)
A representation of the function object.
When using REPL, what will the following line output?
((fn [] “hello world”))
hello world
Clojure’s if-form takes 2 other forms - a then-form and an else-form.
False, it must first take a boolean-form.
Clojure’s else-form in an if-form is optional.
True.
If the 3rd else-form is omitted from an “if” form, what is returned if the boolean-form evaluates to false?
nil
What type of form can be used to group multiple “then” (or “else”) statements into a single expression?
the “do” form.
Which expression in a “do” form is returned by that do form?
The last expression.
What form combines the “if” and “do” forms?
The “when” form.
The “when” form can also optionally accept an else-form.
False, it cannot accept an else-form at all.
“When” forms always return nil when their conditions are false.
True.
What are Clojure’s falsey values?
nil and false.
What are Clojure’s truthy values?
Everything besides nil and false.
