4.6 Fundamentals of Computer Systems (Classification of Programming Languages)

Question 1

What are the 5 classes of programming languages

Answer 1

LOW LEVEL:
1G - Machine Code Language
2G - Assembly Language

HIGH LEVEL:
3G (Imperative) - Python, Java
4G (Declarative) - Database Orientated, SQL
5G - AI

Question 2

What is meant by a low level language

Answer 2

• A programming language with little to no abstraction from a processor’s internal instruction set, and can directly control the computer system hardware

Question 3

What is meant by a high level language

Answer 3

• A programming language with a string absstraction from a processor’s internal instruction set, that is much more human-readable.

Question 4

What is machine code

Answer 4

Lowest-level programming language that a computer’s CPU can execute directly. It consists of binary instructions (0s and 1s) that tell the hardware exactly what to do

Question 5

What are the pros of machine code

Answer 5

• No need for translation and so is faster to execute
• It is more optimisable because there is more control ove the computer system hardware

Question 6

What are the cons of machine code

Answer 6

• Prone to error as one mistake in typing is easier to do
• Harder to debug
• Very time consuming to type 1s and 0s
• not portable as machine code is processor specific

Question 7

What is Opcode and Operand

Answer 7

• 2 parts of a low level language instruction
  Opcode: specifies what process the CPU should perform
  Operand: Specifies the set of values or the memory address that this operation should be excecuted on

Question 8

What is assembly language

Answer 8

Program written using a set of ‘mnemonics’ that represent the binary equivalent in machine code, and has a 1:1 correspondence with machine code language

Question 9

What are the pros of assembly language

Answer 9

• 1:1 correspondence with machine code meaning it is just as optimisable meaning its used usually in embedded systems.
• Require less memory and excecutes faster than high level languages
• mneumonics are easier to understand than binary
• easier to program than machine code

Question 10

What are the cons of assembly language

Answer 10

• not portable as the program is processor specific
• Code can still be difficult to understand
• Can also be very time consuming
• No inbuilt functions like HLL
• Must be translated using an assembler

Question 11

What are The advantages of High level

Answer 11

• easier understand code as the
  keywords are more like natural language.
• They are portable.
• They use a wide variety of inbuilt program structures to make the process of programming and debugging more straightforward and easier to maintain, therefore making development faster
• There is a one-to-many mapping between a HLL statement to machine code often making development time quicker as the same program can be made in less line and so time in HLL language than in machine code

Question 12

What are the disadvantages of high level Languages

Answer 12

• Less optimisable
• Must be translated

Question 13

What is meant by a imperative language

Question 14

What is the link between imperative and low level languages

Answer 14

Programs in both are formed from instructions that specify how
the computer should complete a task

Question 15

What does a Declerative Language entail

Answer 15

A language that provides a given intended result to the user without direct algorithmic instruction from the user of how to excecute it