programming languages keywords

Question 1

What is sequence ?

Answer 1

The order in which code is executed

Question 2

What is selection ?

Answer 2

A programming construct where a section of code is only run if a condition is met ie IF statement

Question 3

What is iteration ?

Answer 3

The repeating of code a specified number of times or until a condition is met ( a loop)

Question 4

What is a high level language ?

Answer 4

A programming language which closely resembles the natural language - the spoken and written language of humans

Examples: Python, Visual basic, Java, C++

Question 5

What is a low level language ?

Answer 5

A programming language close to the computer’s own language

Examples: Machine code and assembly language

Question 6

What language can processors execute instructions in ?

Answer 6

Machine code

Question 7

Will a program written in machine code for a PC run on an Apple smartphone ?

Answer 7

No, because machine code instructions are made specific to a particular processor or group of processors

Question 8

What is assembly language ?

Answer 8

It is a low level language which replaces machine code with mnemonics and operands to make it easier to read and write.

Question 9

What is an operand ?

Answer 9

a term used to describe any object that is capable of being manipulated.

For example, in “1 + 2” the “1” and “2” are the operands and the plus symbol is the operator.

Question 10

What can assembly language be used ?

Answer 10

• In software that is used in embedded systems such as a washing machine
• In software used to control specific hardware components like device drivers

Question 11

What are the advantages of a high level language ?

Answer 11

• Easier to learn
• faster to write
• easier to understand and debug

Question 12

What are the advantages of a low level language ?

Answer 12

• programs can run very quickly
• code usually requires less RAM
• Statements in LLL can be used to control and manipulate specific hardware components

Question 13

What is a translator ?

Answer 13

Translates from one programming language to another

Question 14

What are the three types of translators ?

Answer 14

Interpreter, compiler and assembler

Question 15

What does a compiler do ?

Answer 15

Creates an executable file for a program, source code translated all in one go

Translates from a high level language to machine code

Question 16

What does an interpreter do ?

Answer 16

Translates and executes code line by line

Translates from a high level language to machine code

Question 17

What does an assembler do ?

Answer 17

Assembles the code so that it can be run later

Translates from assembly language to machine code

Question 18

Advantages of a compiler

Answer 18

• Compiled programs run quickly as they have already been translated
• Can be supplied as an executable file which is preferred by programmers, as an executable file cant easily be modified ( without permission)
• Compilers optimise code so that it runs quicker and takes up less memory space

Question 19

What does it mean to optimise code ?

Answer 19

To make the code for a program more efficient.

A program can be optimised to run quicker or take up less memory.

Question 20

What are the disadvantages of compilers ?

Answer 20

• Source code must be recompiled whenever the programmer changes the program
• Source code that is compiled on one platform won’t run on another as the machine code is processor specific.

Question 21

What are the advantages of an interpreter ?

Answer 21

• Instructions are executed as soon as they are translated
• Errors can quickly be spotted ( the user is straight away notified at which part of the program the interpretation has failed)

Question 22

What are the disadvantages of an interpreter ?

Answer 22

• Interpreted programs run slowly as the processor has to wait for each instruction to be translated before it can be executed
• Program has to be translated every time it is run
• Interpreters don’t produce an executable file ( so source code has to be supplied and it could be modified without permission)
• Interpreters don’t optimise code

Question 23

What does a variable do ?

Answer 23

Holds a value in a memory location that is needed to carry out your program

Can only hold one value at a time, value can change.

Question 24

What is an array ?

Answer 24

A data structure that holds similar related data

Question 25

What is a procedure ?

Answer 25

A subprogram that carries out instructions but does not return a value

Question 26

What is a function ?

Answer 26

A subprogram that carries out instructions and returns a value

Question 27

What is an IDE and what can they do ?

Answer 27

Integrated development environments. Make programming easier

• automatically indent code
• highlight important syntax structures
• Can autocomplete lines of code that are typically used
• Can point out any syntax errors that you have made

Question 28

What does an IDE allow you to do ?

Answer 28

Allows you to write, run and debug code without having to switch programs.

Without an IDE, you would have to write all of your programs in a basic text editor.

You would then need to switch programs to translate the code and test it

Question 29

What is declaration ?

Answer 29

To declare a variable as a certain data type ( not used in python)

Question 30

What is initialisation ?

Answer 30

To set an initial value for a variable , which can later be changed

Question 31

What is assignment ?

Answer 31

To change the value held at the variable location

Question 32

What is naming convention ?

Answer 32

The idea that each programming language has their own standard for naming things.