| OCR |
GCSE (9-1) Computer Science
Mark Scheme
J277/02: Unit 2.5 IDE Tools
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| Question | Answer | Marks | Guidance |
|---|---|---|---|
| 1(i) | Displays different parts of the code (keywords, variables, strings) in different colours (1) to make the code easier to read / spot syntax errors (1). | 2 |
Must mention colour or visual distinction. Just saying "highlights errors" is too vague (that's error diagnostics).
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| 1(ii) | Predicts the keyword or function the user is typing and offers to finish it (1). This speeds up coding and reduces spelling/syntax errors (1). | 2 | |
| 2 | Auto-completion / IntelliSense / Code Completion. | 1 |
Do not accept "Spell check".
|
| 3(i) | Underlining the code (e.g., red squiggly line) / Highlighting the line number / Displaying a warning symbol. | 1 | |
| 3(ii) |
1. The code follows the correct rules/grammar of the language (1). 2. The IDE cannot know the programmer's intent / logical purpose (1). |
2 |
Ghost Topic: Students must understand IDEs check grammar, not the intended mathematical logic.
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| 4 | It allows the programmer to run the code one line at a time (1) and see the current values of variables at each step to see where they change incorrectly (1). | 2 |
"Stepping" distinguishes high-level students as it is a specific debugging tool.
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| 5 |
1. Run-time Environment 2. Source Code 3. Machine Code |
3 |
Order must be exactly as listed for full marks.
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| 6 |
1. A compiler produces an executable file (e.g. .exe) (1). 2. This file can run independently without the source code or an interpreter/IDE installed (1). 3. It protects the source code from being seen/edited by the friends (1). |
3 |
Contrast: An interpreter requires translation software to be installed on the destination machine.
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| 7 |
Any two from: - Automatic Formatting: Indents code automatically (1). - Integrated Debugging: Can pause/step through code/watch variables (1). - Project Management: Manage multiple files/folders in one window (1). |
4 |
2 marks per point (1 for identification, 1 for explanation of benefit). Do not accept "It's faster" without specific context.
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| 8 | D (Network Packet Sniffer). | 2 |
Tests recall of the specific J277 specification list of IDE tools.
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