1. 2. 4 Types of Programming Language

Question 1

Programming Paradigms

Answer 1

• This is different approaches to using a programming language to solve a problem
• Two broad categories, imperative and declarative
• Imperative includes procedural and object-oriented paradigms
• Declarative split into logic and functional paradigms
• Paradigm used depends on type of problem that needs solving
• Image gives Visual representation in Word Document

Question 2

Imperative

Answer 2

• Imperative programming paradigms use code that clearly specifies the actions to be performed
• Procedural and Object-oriented paradigms are included

Question 3

Procedural

Answer 3

• Applied to a wide range of problems, relatively easy to write and interpret
• Type of imperative programming which uses a sequence of instructions (may be contained within procedures)
• Instructions carried out step by step
• Examples- Pascal, Python, Logo

Question 4

Object-Oriented

Answer 4

• Applicable to certain types of problem with lots of reusable components which have similar characteristics
• OOP built on objects formed from classes which have certain attributes and methods
• OOP focuses on making programs that are reusable and easy to update and maintain
• Examples- Python, Delphi, Java

Question 5

Declarative

Answer 5

• Focuses on stating desired result rather than exact instructions to get result
• Role of programming language to determine how best to obtain result
• Details about how result is obtained is abstracted from the user
• This type of programming common in expert systems and AI

Question 6

Functional

Answer 6

• Programming that uses the concept of reusing a set of functions that form the core program
• Programs made up of lines of code consisting of function calls
• Function is a named block of code that does a specific task, returns a value
• This type of programming closely linked to maths
• Examples- Haskell, C#, Java

Question 7

Logic

Answer 7

• Logic languages part of declarative programming paradigm
• Use code which defines a set of facts and rules based on the problem
• Queries used to find answers to problems
• Examples- Prolog

Question 8

Procedural Language

Answer 8

• Used for wide range of software development because it is simple to implement
• Not possible to solve all kinds of problems, may be inefficient to use this
• Procedural languages use traditional data types (integers, strings etc), built into language
• Also provides data structures such as dictionaries and arrays
• Structure programming subsection of procedural programming
• Control flow given by 4 main programming structures
• Sequence (ran line by line), Selection (run if specific condition met), Iteration (loop certain number of times or while condition met), Recursion
• Recursion, functions expressed in terms of itself, calls itself till condition known as base case (does not call function) is met
• Procedural programming suited to problems that can easily be expressed as series of instructions using constructs described above

Question 9

Assembly Language (Little Man Computer)

Answer 9

• Next level up from machine code, low level language
• Translated into machine code using assembler when it is executed
• Uses mnemonics, makes it easier to use than machine code
• Each mnemonic represented by numeric code
• Commands used are processor specific due to it having direct interactions with the CPUs registers
• Allows for direct interaction with hardware, therefore useful in embedded systems
• One instruction of assembly code typically equivalent to one line of machine code
• Instructions shown in Word Document

Question 10

Modes of Addressing Memory

Answer 10

• Machine code instructions made up of two parts, opcode and operand
• Opcode specifies instruction to be performed from table above
• Operand holds value which is related to data which instruction is to be performed
• Addressing modes allow greater number of locations for data to be stored
• Size of operand would otherwise constrain number of addresses that could be accessed
• Addressing mode specifies how operand should be interpreted, it is a part of the opcode
• Four addressing modes, Direct, Indirect, Immediate and Indexed

Question 11

The Modes of Addressing

Answer 11

• Immediate addressing is when the operand is the actual value to be operated on, represented by binary
• Direct addressing is when the operand holds a memory address which holds the value to be operated on, this is used in LMC
• Indirect addressing is when the operand gives the address of a register which has another address where the data is located
• Indexed addressing is when an index register is used which stores a certain value, address of operand determined by adding operand to index register
• Necessary to add an offset (integer indicating distance from beginning of object to a given element or point) to access data stored contiguously (in contact, touching) in memory such as arrays

Question 12

Classes, Objects, Methods & Attributes

Answer 12

• Class- blueprint of Object, defines state and behaviour of object
• State given by Attributes- Variables give object properties
• Behaviour defined by Methods associated with class- Describe actions it can perform
• Object instance of a class, class used create multiple objects same attributes and methods (Instantiation)
• Setter sets value of particular attribute
• Getter retrieves value of given attribute
• Ensure attributes cannot be directly accessed and edited (Encapsulation)
• Can only be altered by public methods
• Constructor method- allows new object to be created

Question 13

Inheritance and Polymorphism

Answer 13

• Inheritance process sub class inherits all of the methods and attributes of the super class
• Parent class, Child class Child class can have its own additional properties
• Polymorphism enables objects to behave differently depending on their class, lead to same method producing different outputs, Two categories below
• Overloading- Pass different parameters / variables into a method
• Overriding- Redefine method functions differently produces different output

Question 14

Advantages & Disadvantages OOP

Answer 14

• Advantages- High level of reusability. Code made more reliable through encapsulation, makes code easy to maintain and update, classes can be reused save time and effort
• Disadvantages- Requires alternative style of thinking, not suited to all types of problems, unsuitable for smaller problems