Program Libraries (Cambridge (CIE) A Level Computer Science) : Revision Note

Saves development time

Pre-written routines can be reused, so programmers don’t need to write common functions from scratch

Promotes code reuse

Well-tested routines can be used in multiple programs, reducing duplication

Improves reliability

Library routines are usually thoroughly tested and debugged, reducing the chance of errors

Easier maintenance

Updates to a library routine automatically benefit all programs that use it (especially with DLLs)

Efficient memory usage

Dynamic link libraries (DLLs) are only loaded when needed at runtime, saving system resources

Standardisation

Promotes consistency in how common tasks (e.g. file handling, sorting) are implemented

Program Size

Reduces program size by keeping reusable code separate

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Memory Usage

Saves memory by sharing DLLs between programs

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Code Reuse

Encourages reuse of common routines (e.g. sorting, sound)

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Modularity

Supports modular design for easier development and maintenance

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Ease of Updates

Update a DLL once to improve all programs that use it

Can cause version conflicts if newer DLLs aren’t compatible

Dependencies

External DLLs can be reused by many applications

Program may fail to run if a required DLL is missing

Security

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Malicious or altered DLLs can pose security risks

Debugging

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Errors in DLLs can be hard to trace across multiple programs