design, testing and IDEs

Question 1

what do structure diagrams do

Answer 1

show the smaller tasks of a larger program

Question 2

how are structure diagrams made

Answer 2

by decomposing the program into manageable modules, this modules are then further broken down and eventually into modules that perform individual tasks

Question 3

what are the advantages of using structure diagrams

Answer 3

• coding is easier because you’re only writing the code for simple tasks
• lots of programmers can work on one program
• easier to test your program as each module can be tested individually
• individual sub programs can be fixed and updated without affecting the rest of the program
• you can reuse sub programs

Question 4

how can you make sure a program is well-maintained

Answer 4

• comments explaining what key features of the program do
• indentations to separate different parts of the program
• variables, subprograms and parameters should be named
• using sub programs

Question 5

what should programmers look out for in defensive design

Answer 5

• anticipate how users might misuse their program
• ensure their code in well maintained
• reduce the number of errors in the code through testing

Question 6

what is input validation

Answer 6

checking if data meets certain criteria before passing it into the program

Question 7

what are some of the different types of input validations checks

Answer 7

• range check = checks the data is within a specified range
• presence check = checks the data has actually been entered
• format check - checks the data has the correct format
• look-up table = checks the data against a table of acceptable values
• length check = checks the data is the correct length

Question 8

what is a common way programs use authentication

Answer 8

passwords

Question 9

what is a syntax error

Answer 9

doesn’t follow the rules or grammar of the programming language

Question 10

what is a logic error

Answer 10

able to run the program but the program does something unexpected

Question 11

what are the two types of testing

Answer 11

iterative testing = program is tested while it is being written
terminal testing = program is tested at the end

Question 12

what are the two types of testing

Answer 12

iterative testing = program is tested while it is being written
terminal testing = program is tested at the end

Question 13

what is the advantage of iterative testing

Answer 13

used to identify and fix small errors which help prevent larger errors from occurring later on

Question 14

what is the advantage of terminal testing

Answer 14

modules may work perfectly on their own, but errors may occur when the modules interact which each other

Question 15

what are the 4 different test datas

Answer 15

• normal data = things the user is likely to input into the program
• boundary/extreme data = values at the limit of wha the program should be able to handle
• invalid data = inputs with a correct data type that should be rejected
• erroneous data = inputs with the incorrect data type and should be rejected

Question 16

what are high-level languages

Answer 16

easy for humans to write but computers need to translate it before they can read and run it

Question 17

what are low level languages

Answer 17

tricky for humans to read and write but are easier for computers to run
- machine code
- assembly code

Question 18

what do compliers do

Answer 18

translate high-level code directly into machine code and create and executable file

Question 19

what do interpreters do

Answer 19

take each instruction in the code and call machine code subroutines within their own code to carry out that instruction

Question 20

what are the characteristics of compliers

Answer 20

• translate all the source code at the same time
• only needed once to create an executable file
• returns a list of errors for the entire program
• compiling can take a long time

Question 21

what are the characteristics of interpreters

Answer 21

• translates and runs one instruction at a time and doesn’t create and executable file
• needed every time you run a program
• returns the first error it finds and then stops
• programs run more slowly

Question 22

what are IDEs

Answer 22

Integrated Development Environments
a piece of software that provides features to help a programmer to develop their program

Question 23

what are some features of IDEs

Answer 23

• code editor
• run-time environment
• explorer window
• output window
• error diagnostics and debugging tools
• breakpoints

Question 24

what does the run-time environment do

Answer 24

allows the code to be run quickly within the IDE (start or run button)