UNIT 11: Programming Techniques

Question 1

What does IDE stand for?

Answer 1

Integratred Devlopoment Enviroment

Question 2

facilities of an IDE

Answer 2

Integratred Devlopoment Enviroment is a software which enables you to enter, edit, compile (or interpret) and run your programs

many IDE’s will alos have debugging faciliites to help you find the logic errors in a program

Question 3

Features of an IDE

Answer 3

add line numbers

automatically ident code

auto-complete commands

comment of run-comment a region

finding syntax errors

finding logic errors

debugging facilities

Question 4

debugging facisilities

Answer 4

set a breakpoint (cause the program to stop on that line)

set a watch on a variable so that its value is displayed each time it changes

step through a program one line a time

trace the execution of a program for example display a mesage every time a particular statement is executed or subroutine is called

Question 5

algorithm defintion

Answer 5

an algorithm is a sequence of instructions that can be followed to solve a problem

Question 6

pseudocode defintion

Answer 6

pseudocode is used to write instructions in statements that are somewhere between english and a programming language

guidelines for writing pseudocode no strict rules tho

its an aid

Question 7

variable and assignment

Answer 7

identifier is a name. eg score that points to a memeory location

assignemnet is assigning a value to the memory location

Question 8

varaibles and constants

Answer 8

value of a variable can be changed

to change the value of a constant you have to change it in the source code and then recompile

Question 9

why use a constant

Answer 9

reduce the risk of errors by reducing access to the mmeory location

Question 10

mod and div operators

Answer 10

mod is REMINADER

div is just division

Question 11

if then endif - - - - - - program flow

Answer 11

program flow is controlled by evaluating a boolean condition

boolean condition evaluates to true or false

Question 12

relational operators

Answer 12

> greater than
< less than
=> greater than or equal to
=< less than or equal to
== equal too
!= not equal too

Question 13

complex boolean expressions§

Answer 13

AND returns TWUE is both conditions are true
OR returns TRUE is either of the conditions is true
NOT a TRUE expressions becomes FALSE vice versa

Question 13

if then elseif else endif

Answer 13

if aljdkja;dka

elseif sadfjalskfja

else lasjfkads

endif

Question 14

switch/case .. endswitch

Answer 14

logical equivalent of the
if then else endif statement

switch choice

case a ksldfa;jsdfkja
case b saldjfldas
case c asdlkfjad
default asdlkfja;dkfjs
endswitch

PYTHON NO doesnt have this

Question 15

nested if

Answer 15

in the nested if statement, the second conditioin is only checked if the first condition is true

Question 16

iteration

Answer 16

means repetition

a sequence of instructions is repeated multiple times

this is much more efficient than writing the instructions mulitple times

the number of repetitions needed may vary and may not be known when writing the code

Question 17

while endwhile loop

Answer 17

condiiton is tested upon entry to the loop

its possible that the instructions inside the loop might not be executed at all if the entry condition is not met

Question 18

do until loop

Answer 18

statements in the loop are excuted before the condition is evaluated
not in python
equgialent is while.. end while loop

Question 19

infinite loop

Answer 19

you may make one if u make a damn error

brief pause can be included to slow down the loop

computer xontrol and data sendsing appliocations use infinite loops to gather data from sensors

• varitety of sensors can control a number of output dvices such as lights, buzzers and motors
• after the setup code is run the device enters an infiinite loop to repeatedly check the value of the sensors.

Question 20

for.. next loop

Answer 20

termed ‘definite iteration’ and is used to repeat a block of insturctions a specififed number of times

uses a counter variable which is automatically incrememnted each time through the loop

optionally a step value can be specified to make the counter increase or decrease by any integer

Question 21

nested for .. next loop

Answer 21

it is possible to use nested for loops

useful for looping through grids in two dimensional arrays

Question 22

subroutine

Answer 22

set of instructions with a name

Question 23

built in functions

Answer 23

programming lanugages come with many built in functions which perform common tasks

Question 24

library subroutines

Answer 24

programming languages also come complete with libraries of pre-defined subroutines the module library has to be imported at the start of the program import random ahh subroutine import

Question 25

passing arguments

Answer 25

arguments in parentheses are used to pass data into a subroutine procedure multiply(x,y)

Question 26

parameters and arguments

Answer 26

both terms are used interchangeably strictly speaking, parameters appear in subroutine definitions, and arguments appear in subroutine calls parameter (x,y) argument - when called

Question 27

passing by value

Answer 27

in python all arguments are passed by value means that the actual value of the argument in the calling statement is copied to the variable parameter in the subroutine any calc perfomred on that parameter in the subroutine will not affect the value of the corresponding argument in the calling routine

Question 28

passing by refrence

Answer 28

some programming languages allow arguments to be passed by value or by reference by reference means that the address of the argument in the calling statement is passed to the corresponding parameter in the subroutine any caluculation perfomred on the parameter in the subroutine will change the value of the corresponding argumnet in the calling routine

Question 29

variable scope

Answer 29

determines where a variable can be accessed within a program

Question 30

local variables

Answer 30

a subroutine may have its own variables local variable can only be used in that subroutine

Question 31

global variables

Answer 31

defined in the main perogram and can be used in any subroutine called from the main program

Question 32

scope of variables (local and global)

Answer 32

scope of a local variable is the subroutine in which it is declared global is everywhere duh

Question 33

advantages of local variables

Answer 33

subrroutines will be indepdnet of a particular program and can be reused else where no chance of accodenetally changing a variable in the main program that is used in a subroutine or vice versa

Question 34

modular programming

Answer 34

means breaking down a major task into smaller subtasks these subtasks may be further broken down until each module performs a singular function

Question 35

advantages of modular programming

Answer 35

programs are more easily and quickly written large programs are broken down into subtasks that are easier to program and manage each module can be individually tested modules can be re-used several times in a program large programs are much easier to debuh and maintain

Question 36

factorials

Answer 36

5! (5 factorial) 5x4x3x2x1

Question 37

recursion

Answer 37

factorial function is a good example of a function that can be defined in terms of itself n! = n x (n-1)!

Question 38

essential characteristics or a recusive routine (3 of them)

Answer 38

a stopping condition or BASE CASE must be included which when met meanas that the routine will not call itself and will start to unwind for input values other than the stopping condition, the routine must call itself the stopping condition must be reached after a finite number of calls

Question 39

stack overflow!

Answer 39

occurs when a computer program tries to use more memory space in the call stack than has been allocated to that stack.

Question 40

use of the call stack

Answer 40

every time a subroutine is called, the return address (line after call statement) is put on the call stack even with a stopping condition the recusive routine can only be called a limited number of times or the stack will overflow the maxium memory capcity

Question 41

recursive fibonacci (more info)

Answer 41

each number is found by adding the two precceeding numbers

Question 42

recursive vs iterative routines

Answer 42

recursive can casue stack overflow recusrive usually have fewer lines iteerative is easier to follow iterative geenrally exccute faster iterative is more faster usually

Question 43

OOP

Answer 43

object oriented programmiing

Question 44

classes - OOP

Answer 44

class is a blueprint for an object it defines what an object in the class will look like (its properties) and what it can do A class may implement an abstract data type such as an array or fraction or a more concrete object such as a person or car

Question 45

attributes and methods - OOP

Answer 45

class will define the attributes of objects in the class it will also define methods (procedures) that an object in the class can perform

Question 46

public and private - OOP

Answer 46

attributes are normally declared as private methodds are public usually this is to ensure that attributes cannot be changed except by executing a method

Question 47

encapsulation and data hiding

Answer 47

enca[psulation wraps the attributes and methods in the class defintiiotn hiding details of the implementation from the user

Question 48

setter and getter methods

Answer 48

we often need a means to set an attribute or to find out the value of an attribute data hiding - means programmer who dfines an object in a class cannot directly access or change an attribute of an object it has to be done via a getter or setter method

Question 49

inheritance

Answer 49

ability to define child classes which inherit the attributes and methods of a parent class arrows always towards the parent class

Question 50

polymorphism

Answer 50

inherited class may redefine methods that are defined in the parent class ability of a programming language to process objects differently depdning on their class is called polymorphism

Question 51

advantages of OOP

Answer 51

code reuse - classes created in one program can esasily be saved to a library and resused in other programs - leads to faster program development encapsuslation reduces code completxity - once an object is created it is not necessary to know how its methods are implrmenented, attirubutese can be hidden from useres so that they cant change them accidentally software maintenace - easay to modify and maintain