2.7 Fundamentals of functional programming

Question 1

Define functional programming paradigm

Answer 1

A language where each line of code is made up of calls to a function, which in turn may be made up of other functions, or result in a value

Question 2

Define declarative programming languages

Answer 2

Languages that specify what properties a result should have, e.g. results based on functions

Question 3

Define procedural programming languages

Answer 3

Languages where the programmer specifies the steps that must be carried out in order to achieve a result

Question 4

What are the benefits of a functional programming paradigm?

Answer 4

• Program requirements may be better defined as a series of abstractions based on functions
• Broader abstractions can lead to fewer errors in implementation
• Functions can be applied at any level of data abstraction making them highly reusable within a program
• Functional code is easier to test and debug
• There are no concurrency issues
• In multi-processor environments, the order functions are evaluated in is not critical

Question 5

Define function type

Answer 5

Refers to the way in which the expression is created, for example, integer of the domain and co-domain where f: a->b is the type of function, a is the argument type and b is the output type

Question 6

Define domain

Answer 6

A set of data of the same type which are the inputs of a function

Question 7

Define co-domain

Answer 7

The set of values from which the outputs of a function must be drawn

Question 8

Define first-class object

Answer 8

Any object that can be used as an argument or result of a function call

Question 9

Define higher order function

Answer 9

A function that takes a function as its inputs or creates a function as its output

Question 10

Define function application

Answer 10

The process of calculating the result of a function by passing it some data to produce a result

Question 11

Define partial application of a function

Answer 11

The process of applying a function by creating an intermediate function by fixing some of the arguments to the function

Question 12

Define function composition

Answer 12

Combining two or more functions to create more complex functions

Question 13

Define map function

Answer 13

A function that generates an output list from an input list by applying a function to each element in the input list

Question 14

Define filter function

Answer 14

A method of creating a subset based on specified criteria

Question 15

Define reduce / fold function

Answer 15

A method of reducing a list to a single element by combining the elements using a function