Arrays

Study Notes

An array is a data structure that stores multiple items of the same data type using index numbers. Arrays have a fixed size defined during declaration.

• Array — a data structure capable of storing multiple items of data at a time. Example: An array named 'fruits' can store items like 'Apple', 'Orange', 'Strawberry'.
• Index — a unique storage slot for each element in an array. Example: In the array 'fruits', 'Strawberry' is at index 2.
• 1-Dimensional Array — a basic array type that can be considered as a simple list of items. Example: DECLARE Fruits : ARRAY[0:4] OF STRING
• 2-Dimensional Array — can be considered as a table structure, defined as arrays within an array. Example: DECLARE StudentMarks: ARRAY[0:4, 0:3] OF INTEGER
• List — in Python, a collection that can contain different data types and does not require a fixed size. Example: A list can grow or shrink as needed.

Exam Tips

Key Definitions to Remember

• An array is a data structure that stores multiple items of the same data type.
• An index is a unique storage slot for each element in an array.
• A 1-Dimensional array is a simple list of items.
• A 2-Dimensional array is a table structure, or arrays within an array.
• A list in Python can contain different data types and does not require a fixed size.

Common Confusions

• Confusing arrays with lists in Python, as lists can store different data types and are not fixed in size.
• Forgetting that arrays have a fixed size and must be defined during declaration.

Typical Exam Questions

• What is an array? An array is a data structure that stores multiple items of the same data type using index numbers.
• How do you access an element in an array? Use the array name followed by the index number, e.g., fruits[2] for 'Strawberry'.
• What is the difference between a 1-D and a 2-D array? A 1-D array is a simple list, while a 2-D array is a table structure with arrays within an array.

What Examiners Usually Test

• Understanding of how to declare and initialize arrays.
• Ability to differentiate between arrays and lists in Python.
• Knowledge of accessing and modifying elements within arrays.