2.3 Producing robust programs

Question 1

What are structured diagrams?

Answer 1

They are diagrams showing smaller tasks in larger program

Question 2

Why use structure diagrams?

Answer 2

• easier for programmer as they can work on sections at a time
• Improves organisation

Question 3

What are the advantages of using structure diagrams?

Answer 3

• coding is easier as each part is simple
• easier to test individually
• easier to spot issues to fix and update them
• reuse subprograms in future

Question 4

How to make the program have more maintainability?

Answer 4

• Comments - explain each key feature of a program
• indentation - makes control flow clearer
• variable names - should be relevant fir better understanding
• Sub Programs - Makes code more understandable as it is split up.

Question 5

What is defensive design?

Answer 5

When programmers protect their program

Question 6

How can programmers protect their code?

Answer 6

Predict misuse
ensure code is well maintained
reduce errors through extensive testing

Question 7

What are the methods that programmers can use to protect their code?

Answer 7

Input validation

Authentication

Question 8

What are the type of checks that input validation uses?

Answer 8

Range
Presence
Format (eg a date)
length 
look-up table

Question 9

What is input validation?

Answer 9

Is checking data meets criteria before passing it on

Question 10

What is Authentication?

Answer 10

Confirms the user identity before they’re able to access certain areas of the program (passwords)

Question 11

What are the common ways to increase the security on passwords?

Answer 11

• use strong passwords - combination of number and letters
• limit for failed authentication attempts
• ask for random selection of characters

Question 12

What is syntax errors?

Answer 12

where the interpretor doesn’t understand something due to a grammatical mistake

Question 13

What is logic errors?

Answer 13

Is where the program runs, but does something unexpected

Question 14

What is the difficulty of diagnosing syntax errors and logical errors?

Answer 14

Syntax error - easy to identify as complier returns the error and location.
Logical error - harder to track as they are not picked up by compliers

Question 15

What are the 2 type of testing?

Answer 15

iterative testing

Final (terminal) testing

Question 16

What is Iterative testing?

Answer 16

Is testing while the programing is being developed

Question 17

What is Final testing?

Answer 17

The program is tested at the end of the development process. The whole program is tested at the same time to check that it is working correctly.

Question 18

What is a Test plan?

Answer 18

Outlines exactly what you are testing and how you’re intended to do that.
(A good test plan anticipates potential issues)

Question 19

What are the 4 test datas?

Answer 19

Normal data
Boundary data
Invalid data
Erroneous data

Question 20

What is normal data?

Answer 20

Things that a user is likely to input

Question 21

What is Boundary data?

Answer 21

Values at the limit of what a program can handle.

Question 22

What is invalid data?

Answer 22

Data that should be rejected

Question 23

What is erroneous data?

Answer 23

use of incorrect data type and should be rejected

Question 24

What is machine code?

Answer 24

0 and 1s (binary)

Question 25

What is high level language?

Answer 25

easy for humans to understand and are programming languages such as python.

Question 26

What is low level language?

Answer 26

Hard for humans to read nd write but are easier for the computer to run. It has machine code and assembly languages.

Question 27

Comparison of high level language and low level language.

Answer 27

• instructions - high level has one instruction that represents many lines of machine code. Low level has one instruction is one line of machine code
• Readable - High level is easy to read and understand. low level is hard to read and understand.
• CPU internal structure - high level doesn’t need CPU internal structure knowledge. Low level has internal structure of CPU knowledge needed
• translation - high level requires translation before the computer can understand. Low level doesn’t need translation.

Question 28

The difference between compliers and translators

Answer 28

Translates - complier uses all source code at once and creates an EXE file but translator translates and run code line by line.

Returns- complier returns list or errors for entire program but translator returns first error it finds.

speed - complier the compiling is long but runs quickly when done but translator runs slow.

Question 29

What is a Integrated Development Environment?

Answer 29

Are pieces of software that help programmers develop a program.

Question 30

What are examples of IDE’s?

Answer 30

Syntax Completion
Run-time environment
breakpoints
Version control
Error diagnostics
stepping

Question 31

What is syntax completion?

Answer 31

Uses Al to predict what you’re writing and gives option for completion

Question 32

What is run-Time environment

Answer 32

Allows code to be quickly run within the IDE

Question 33

What is breakpoints

Answer 33

Runs code until a set “breakpoint”

Question 34

What is version control?

Answer 34

Allows you to quickly switch between versions of the programming language you are using.

Question 35

What is Error diagnostics

Answer 35

Helps find and fix errors in a program

Question 36

what is Stepping?

Answer 36

Runs code line by line.