Component 7 - Key Definitions

Question 1

Need for and characteristics of a variety of programming paradigms

Answer 1

Paradigms are the concepts on which a language are built, but simply just boils down to “different ways of doing the same thing.” In terms of programming it is the study of/acknowledgment that different languages may achieve the same things in different ways and there are subtle advantages/disadvantages to this.
Each language has its own specific goal – Some are aimed at logic and mathematical modelling (R for example), some are designed to be as safe as possible for mission critical systems, some focus on AI such as LISP and so forth. Each tailors its syntax, key words and structure to best suit the intended application. Bottom line – recognise that whilst you can do something in a language, doesn’t always mean you should or that it’s the “correct” language for the job

Question 2

Procedural languages

Answer 2

Procedural languages are those which are designed to create programs which are structured in small “blocks” of code called procedures or functions. A Procedure is simply a block of code, with a name, which can be “called” from anywhere within the code. They have the obvious advantage of simplicity of design and the fact that these code blocks can be reused.
Procedural languages are intrinsically linked to the concept of Stacks – each time a procedure is called, the current state of the program must be pushed to the stack. There are hardware and software implications of this

Question 3

Assembly language (including following and writing simple programs with the Little Man Computer instruction

Answer 3

Assembly language consists of short three or four letter mnemonics which directly represent a machine code CPU instruction. It exists purely to make machine code programming human accessible. Instead of writing programs in pure binary, we can write in assembly language and then use an assembler to convert the code back into binary. One of the earliest/first types of programming language.
LMC is a “learning language” designed to introduce you to assembly through 10 simple commands and is essential that you practise for your exam.

Question 4

Modes of addressing memory (immediate, direct, indirect and indexed).

Answer 4

When issuing an assembly language instruction, it usually comes in the form Operator – Operand, or more simply Instruction, Data.
The data in an instruction can either be: A number
An address
An offset
The type of data is determined by its “addressing mode” which is represented by a symbol.
Immediate: interpret as a number
Direct: interpret as an address
Indirect: an address which, when visited in memory, holds the address we actually want Indexed: a base address which we then add an offset to, in order to find the address we want

Question 5

Object-oriented languages (see appendix 5e for pseudocode style) with an understanding of classes, objects, methods, attributes, inheritance, encapsulation and polymorphism.

Answer 5

Object-oriented programming (OOP) is a programming paradigm based on the concept of “objects”, which can contain data and code: data in the form of fields (often known as attributes or properties), and code, in the form of procedures (often known as methods).
There are countless object oriented languages, most commonly Java, C++, C# and Python