A Level Computer Science OCR Practice Exam

What are library routines in programming?

1. Custom functions created by the programmer

2. Functions built into programming languages that are tested and error-free

3. External algorithms downloaded from the internet

4. Libraries that store code for larger applications

The correct answer is: Functions built into programming languages that are tested and error-free

Library routines are functions that are built into programming languages and are typically provided as part of a standard library. These routines are pre-tested, meaning they are designed to be reliable and error-free, addressing common programming tasks such as mathematical calculations, string manipulation, or input/output operations. Using library routines allows programmers to avoid reinventing the wheel, enabling them to implement these essential features without having to write every piece of functionality from scratch. It enhances efficiency and maintainability in code development, as these routines are optimized and provide standardized ways of interacting with the language’s features. In contrast, custom functions created by the programmer can vary in quality and reliability since they may not have undergone the same level of scrutiny. External algorithms downloaded from the internet may or may not be trustworthy and might require additional verification. Libraries that store code for larger applications may encompass a wide variety of functionalities but do not specifically define routine functions tested and built into programming languages. Therefore, the answer accurately reflects the nature of library routines in the context of programming.