Process
WJEC AS-Level Computer Science 601-5345-3
Hardware: Architecture, Memory and Storage
Networks and Data Transmission
Logic Gates and Boolean Algebra
Data Representation and Data Types
Data Structures
Organisation of Data: Files and Records
Database Systems
The Operating System
Algorithms and Programs
Principles of Programming
Systems Analysis
Software Engineering and Program Construction
Topic overviewIntegrated development environments and their purposeEditors, syntax highlighting and code entry toolsDebugging tools: breakpoints, stepping and watchesTranslation, source code and object codeLexical analysis and the symbol tableSyntax and semantic analysisCode generation and optimisation
Types of Software System
Practical Programming
Data Security and Integrity
Computing, Society and the Law
Topic overviewSocial and economic change from computingComputers and the nature of employmentThe digital divide and cultural changeEnvironmental cost of computingData protection and freedom of information lawThe Computer Misuse Act 1990 and computer crimeCopyright, surveillance and professional codes
Software Engineering and Program Construction
- 7 subtopics
- 21 things to know
- AS Unit 1
What Software Engineering and Program Construction covers
Software Engineering and Program Construction is examined in AS Unit 1, Fundamentals of Computer Science. It covers integrated development environments and their purpose, editors, syntax highlighting and code entry tools, debugging tools: breakpoints, stepping and watches, translation, source code and object code, lexical analysis and the symbol table, syntax and semantic analysis and code generation and optimisation.
Where it is assessed
AS Unit 1
Fundamentals of Computer Science, examined again at A2 at a more demanding level.
Check the WJEC specification ↗The 7 subtopics
Each one has its own page. WJEC AS Computer Science students sit this topic in the first year.
- Integrated development environments and their purposeIntegrated development environment, context-sensitive help and run-time environment within a development package.Open →
- Editors, syntax highlighting and code entry toolsSyntax highlighting, bracket matching and what automatic indentation does for the reader of a program.Open →
- Debugging tools: breakpoints, stepping and watchesStepping into a subroutine call and stepping over it, why a debugger finds logic errors that the translator cannot and variable trace.Open →
- Translation, source code and object codeSource code, object code and term translator.Open →
- Lexical analysis and the symbol tableFirst stage of the compilation process, two things a lexical analyser removes from the source program and error can be detected during lexical analysis.Open →
- Syntax and semantic analysisFaults that syntax analysis would report and type error found by semantic analysis.Open →
- Code generation and optimisationWhy one high-level statement often becomes many machine instructions, purpose of the optimisation stage and what is meant by removing dead code.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
What does an integrated development environment bring together, and what does that save the programmer doing?
Key term
Explain why checking types before the program runs is safer than checking them as it runs.
Key term
Explain how syntax highlighting helps a programmer spot a missing quotation mark.
Key term
Explain how a conditional breakpoint helps when a loop runs thousands of times.
Process
Why must a high-level language program be translated before a processor can run it?
Key term
Explain why one high-level statement often becomes many machine instructions.
Key term
Name four facilities you would expect to find in an integrated development environment.
Key term
What is bracket matching?
Key term
How would single stepping reveal a loop that repeats one time too many?
Key term
Define the term translator.
Process
What is the first stage of the compilation process?
Key term
Give two examples of faults that syntax analysis would report.
Key term
Explain how a multiplication by a power of two can be optimised.
Key term
Why does working inside one environment shorten the write, translate and run cycle?
Key term
What is autocompletion in a code editor?
Key term
Why is using a debugger usually better than inserting statements that print values?
Key term
Explain why a program that has been compiled usually runs faster than the same program under an interpreter.
Key term
State four items of information a symbol table entry may hold.
Key term
What is parsing?
Key term
Why must an optimisation never change the meaning of a program?
Take Software Engineering and Program Construction further
The same content, four other ways.
Questions from this topic
Each one with the model answer underneath.
- 1
What is an integrated development environment?
Model answer
It is a single application that gathers together the tools a programmer needs, typically an editor, a translator, a debugger and a run facility, so a program can be written, translated, run and corrected without leaving one piece of software.
- 2
Name four facilities you would expect to find in an integrated development environment.
Model answer
A source code editor, a translator that turns the code into a runnable form, a debugger for finding faults, and automatic error reporting linked to the line at fault.
- 3
Why does working inside one environment shorten the write, translate and run cycle?
Model answer
The whole cycle is driven from one set of menus or keystrokes, so the programmer does not have to save the file, switch to a translator, then switch again to run the result.
- 4
What does it mean to build a program in a development environment?
Model answer
Building translates all the source files that make up the program and joins them, together with any libraries used, into a single runnable program.
- 5
Explain how a development environment manages a program made of several files.
Model answer
It holds them together as a project, records which libraries and settings the program needs, and can retranslate only the files that have been changed since the last build.
- 6
Why is the ability to jump straight from an error message to the offending line valuable?
Model answer
It removes the work of counting lines by hand, so the programmer sees the faulty statement in context immediately and can correct it while the error message is still on screen.
What is inside Levo
Six ways to work the same material.
Software Engineering and Program Construction revision questions
- Is Software Engineering and Program Construction examined at AS in WJEC Computer Science?
- Yes. It sits in AS Unit 1, which you take in the first year, so it is on the AS paper as well as counting towards the full A level.
- What does Software Engineering and Program Construction cover in WJEC AS-Level Computer Science?
- 7 subtopics: integrated development environments and their purpose, editors, syntax highlighting and code entry tools, debugging tools: breakpoints, stepping and watches, translation, source code and object code, lexical analysis and the symbol table, syntax and semantic analysis and code generation and optimisation. Each one has its own page with questions and model answers.
- How is Software Engineering and Program Construction organised?
- By the WJEC 601-5345-3 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Software Engineering and Program Construction, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
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