Computer Science 考试技巧

计算器程序

常见错误

1. 1high涉及分数: 2Computational thinking

   Calling getNext() multiple times within a single iteration loop when traversing collections.

   如何避免: Call getNext() exactly once per iteration, store the returned object in a temporary variable, and perform all subsequent logical comparisons and operations on that variable.
2. 2high涉及分数: 4Object-oriented programming (OOP)

   Accessing attributes or calling methods on array objects without executing a null pointer sentinel check, leading to runtime NullPointerExceptions.

   如何避免: Implement an explicit check 'if (array[i] != null)' to ensure the index actually holds an instantiated object reference before performing any operations on it.
3. 3high涉及分数: 3Object-oriented programming (OOP)

   Violating encapsulation by accessing private object properties directly across class boundaries instead of using defined public accessor methods (getters).

   如何避免: Always invoke public getter methods (e.g., s.getArtworkPrice()) when accessing attributes from foreign class scopes.
4. 4medium涉及分数: 3Computational thinking

   Failing to update all parallel arrays simultaneously during sorting algorithms, resulting in desynchronized and corrupted relational data.

   如何避免: Construct swap operations using temporary storage variables that swap elements across all associated parallel arrays at the exact same index.
5. 5medium涉及分数: 6System fundamentals

   Providing one-sided, feature-list descriptions for 'compare and contrast' or 'evaluate' command words, rather than structured, balanced comparative analyses.

   如何避免: Use explicit comparative syntax ('whereas', 'unlike') and ensure you analyze both similarities/differences or advantages/disadvantages before writing a reasoned conclusion.