3.2 Programming

Question 1

Data types

Answer 1

Programming languages store data as different types and they are dealt with differently by the program.

Question 2

INT

Answer 2

Integer - whole numbers, positive and negative

Question 3

REAL

Answer 3

Numbers that have a decimal point- sometimes called FLOAT

Question 4

BOOLEAN

Answer 4

Can have one of two values - true/false, yes/no, 1/0

Question 5

CHAR

Answer 5

Character - a single letter, number or symbol

Question 6

STRING

Answer 6

Used to represent text - it is a collection of characters

Question 7

Casting

Answer 7

Changing one data type to another, e.g. converting string to integer

Question 8

DIV operator

Answer 8

Returns the whole number part of a division, e.g. 5 DIV 2 = 2

Question 9

MOD operator

Answer 9

Returns the remainder part of a division, e.g. 5 MOD 2 = 1

Question 10

Assignment

Answer 10

Assigning a value to a variable or constant, e.g. total=25 assigns the value 25 to the variable total

Question 11

Comparison operator

Answer 11

Compares the left hand side of an expression to the right hand side, e.g. 4<10 (is 4 less than 10)

Question 12

Same as?

Answer 12

Python uses ==

Question 13

Not the same as?

Answer 13

Python uses !=

Question 14

Variable

Answer 14

A named data store which can change as the program is run

Question 15

Constant

Answer 15

A named data store which cannot be changed as the program is run, e.g. pi

Question 16

Local variable

Answer 16

A variable that is only defined and usable in certain parts of a program

Question 17

Global variable

Answer 17

A variable that can be used throughout the whole program

Question 18

Selection

Answer 18

A decision/way of controlling a program using a selection statement, IF - THEN - ELSE

Question 19

Nested IF statements

Answer 19

Using an IF statement inside another one.

Question 20

ELIF

Answer 20

Used where there is more than one option in a selection statement. Short for ELSE - IF

Question 21

Iteration

Answer 21

A way of repeating a set of instructions - can be a based on a condition or a number of repetitions

Question 22

FOR LOOP

Answer 22

A count controlled loop

Question 23

Array

Answer 23

A data structure that can store a group of data values of the same time. A one-dimensional array could be called a LIST. A two-dimensional list could be called a TABLE.

Question 24

Subroutine

Answer 24

A set of instructions stored under one name which can be used (called) when you want the program to use them

Question 25

Functions

Answer 25

Subroutines that return a value

Question 26

Procedures

Answer 26

Subroutines which do not return a value

Question 27

Structured programming

Answer 27

Breaking down a complex problem into more manageable sub-problems and using subroutines for these.

Question 28

Robust programming

Answer 28

This protects against unexpected inputs or actions, ensures that users are allowed to enter data and tests for bugs/problems

Question 29

Authentication

Answer 29

Used to confirm the identity of the user and includes passwords

Question 30

Validation

Answer 30

revents the accidental or intentional misuse of a program when entering data, e.g. the use of range, presence, format checks, lookup tables and length checks

Question 31

Testing

Answer 31

Allows the writer of the program to check for syntax and logic errors

Question 32

Algorithm efficiency

Answer 32

Different algorithms can perform the same taks. The efficiency is less about the lines of code and more about, for example, the number of times a loop was executed or memory accessed.

Question 33

Trace tables

Answer 33

Allows you to test that a piece of code is working correctly by tracking the values that certain variables take as you go through the code.

Question 34

High level computer language

Answer 34

Easy for humans to write, e.g. Python

Question 35

Low level computer language

Answer 35

Easy for computers to run, e.g. machine code and assembly language

Question 36

Translators

Answer 36

Necessary to translate high level languages into machine code. There are 3 types of translator - assemblers, compilers and interpreters

Question 37

Machine code

Answer 37

The lowest level language consisting of 1s and 0s

Question 38

Compilers

Answer 38

Translate all the code at the same time. Can take a long time to compile but once compiled runs the program quickly

Question 39

Interpreters

Answer 39

Translates and runs the source code one line at a time. This has to be done every time you run the program and runs more slowly

Question 40

Assemblers

Answer 40

Turns assemby language into machine code - each language needs its only unique assembler