1.2.4 Types of Programming Languages

Question 1

What is a programming paradigm?

Answer 1

A style or a way of programming.

Question 2

What is machine code?

Answer 2

• The least abstract - closest to what happens on a computer
• Directly into binary
• These translate into matching electrical signals
• One to one relationship

Question 3

What are high-level programming languages?

Answer 3

Types of programming languages that are more closer to natural language, making it easier for humans to understand.

They have a many-to-one relationship, as each instruction of code is equivalent to many lines of machine code. Thus they are more complex.

Question 4

What are low-level programming languages?

Answer 4

Types of programming languages that provide little or no abstraction from the machine instructions, allowing programmers to manipulate hardware elements (register, memory etc).

Question 5

What are the types two types of low-level programming languages?

Answer 5

• Machine code
• Assembly

Question 6

What is assembly?

Answer 6

• Uses mnemonics (match to a specific of 1s and 0s)
• One to one relationship
• Written in assembly language and translated by a specific assembler
• Uses symbolic addressing as labels to reference data locations
• Data is accessible to other parts of the program using parameter passing

Question 7

What are the advantages of low-level languages?

Answer 7

• Assembly and machine have the same efficiency through 1-1 nature
• Very precise, locally optimised and efficient code
• You are in complete control of the code
• Provides access to system level features without going through system interface, improving program speed

Question 8

What are the disadvantages of low-level languages?

Answer 8

• Machine-dependent and code is very hard to port
• Programmers to write efficient assembly code are rare
• Even for a talented programmer, code is tedious to write and very prone to bugs
• Code can be difficult to understand, so it’s hard to modify and maintain

Question 9

What are the two categories of high-level languages?

Answer 9

• Declarative
• Imperative

Question 10

What are declarative languages?

Answer 10

They focus on what a program is required to do, but not how they do it.

Question 11

What are imperative languages?

Answer 11

They use statements that change the program’s state in the form of sequence, selection and iteration. They consist of commands for a computer to perform and focus on describing how a program operates.

Question 12

What are the features of a procedural language?

Answer 12

• Sequence, selection and iteration
• Data stored in local/global variables
• Data accessible by addressing specific memory locations
• Structured into procedures and functions
• Logic is expressed in a series of procedure calls

Question 13

What are the features of an object-oriented language?

Answer 13

• SSI + inheritance, objects, classes and encapsulation
• Data stored in attributes
• Data concealed from other parts of the program via encapsulation
• Programs structured into classes, methods and instances (objects)
• Logic is based on models and behaviours

Question 14

What is a procedural (imperative) language?

Answer 14

One of the most common programming paradigms in use. They focus on telling a computer exactly what to do by sequential instructions.

Question 15

What is a local variable?

Answer 15

A variable that can only be accessed within the specific subroutine it was declared in.

Question 16

What is a global variable?

Answer 16

A variable that cab be accessed throughout the entire program and is used by all modules during execution.

Question 17

What is parameter passing?

Answer 17

Allows variables values to be passed into subroutines for use in these blocks of code.

Question 18

What is modularity?

Answer 18

The concept of separating the functionality of a program into small, interchangeable blocks - each designed to carry out a specific task.

These all combine to make a complete program and make the program more readable.

Question 19

What is a library?

Answer 19

A collection of pre-built functions and procedures that can be linked and used by a programmer in their own code.

Question 20

What is immediate addressing (immediate operand)?

Answer 20

The actual value (immediate data) is specified in the operand rather than referring to the content of a memory address or a register.

Question 21

What is direct addressing?

Answer 21

The value of the operand is a reference to the address in memory where the contents are loaded into the accumulator.

Question 22

What is indirect addressing?

Answer 22

The operand, or the data to be manipulated, is not directly specified in the instruction.

Instead, the instruction contains a reference to the memory address that holds the actual operand.

Question 23

What is index addressing?

Answer 23

The operand, or the data to be manipulated, is located at an address calculated by adding a constant offset (index) to a base address.

Question 24

Why do we need different types of addressing?

Answer 24

Various addressing modes allows programmers to tailor their instructions to the specific needs of a program, enhancing versatility, efficiency, and overall performance.

Question 25

What is an index register?

Answer 25

An index register is a register that holds a value representing a memory address.
This is used to find specific items in data structure (arrays).

Question 26

Why is an index register used in indexed addressing?

Answer 26

Instead of looking through the entire list one by one, the computer can use the index register to jump directly to the address of the first item of the array, increasing efficiency and speed when accessing required data.

Question 27

What is the OPCODE?

Answer 27

A specific binary value that represents a single instruction from the processor’s instruction set.​

Question 28

What is the OPERAND?

Answer 28

Represents the data to be operated on or manipulated by some type of operator.​

Question 29

What is object-oriented programming?

Answer 29

A paradigm, involving the attempt to capture or group information, data and related functionality into structure items known as objects.​

Question 30

What is a class?

Answer 30

A template for creating objects. It defines the attributes and behaviors that the instantiated objects will have.

Question 31

What is a superclass (base class)?

Answer 31

The class from which a subclass inherits its attributes and behaviours.

It is higher in the class hierarchy and provides a common set of features that multiple subclasses can share.

Question 32

What is an object?

Answer 32

An instance of a class which represents a real-world entity, combining data (attributes) and the actions (methods) that can be performed on that data.

Question 33

What is inheritance?

Answer 33

A mechanism that allows a new class (subclass or derived class) to inherit attributes and behaviours from an existing class (base class) and add further functionality to it.

It promotes code reuse and the creation of a hierarchy of classes.

Question 34

What is instantiation?

Answer 34

The process of creating an instance (object) of a class.

It involves allocating memory and initializing the object based on the structure and behaviour defined by the class.

Question 35

What is polymorphism?

Answer 35

The ability for methods of the same name to be used in inherited classes with different behaviours exhibited.

Question 36

What is encapsulation?

Answer 36

Data held within a class (attributes) that can only be accessed via its methods.

They cannot be accessed directly, thus promoting data hiding and the principle of information hiding.