Arrays and lists in Intro to Computing - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an array?

An array is a collection of items stored at contiguous memory locations. Think of it like a row of mailboxes where each mailbox holds one item and has a number (index) to find it quickly.

beginner

How is a list different from an array?

A list is like a flexible container that can hold items of different types and can grow or shrink in size. An array usually holds items of the same type and has a fixed size.

beginner

What does 'index' mean in arrays and lists?

An index is a number that shows the position of an item in an array or list. It usually starts at 0, so the first item is at index 0, the second at index 1, and so on.

intermediate

Why do arrays have fixed size?

Arrays have fixed size because they reserve a block of memory all at once. This makes accessing items fast but means you can't add more items than the size you set.

beginner

Give a real-life example of a list.

A shopping list is a good example. You can add or remove items anytime, and the list can have different types of things like fruits, bread, or cleaning supplies.

What is the starting index of an array in most programming languages?

A 1

B 0

C -1

D Depends on the language

Most programming languages start array indexes at 0, meaning the first element is at position 0.

Which of these is true about lists compared to arrays?

A Lists have fixed size

B Lists always hold only numbers

C Lists can change size dynamically

D Lists store items in random order

Lists can grow or shrink as needed, unlike arrays which usually have a fixed size.

If you want to access the third item in a list, which index do you use?

A 2

B 3

C 1

D 0

Since indexing starts at 0, the third item is at index 2.

Why might you choose an array over a list?

A When you need fast access and fixed size

B When you want to store different types of data

C When you want to add items anytime

D When you want to store items in no order

Arrays provide fast access because of fixed size and contiguous memory.

Which of these is NOT a characteristic of arrays?

A Fixed size

B Contiguous memory storage

C Indexed access

D Can hold different data types easily

Arrays usually hold items of the same data type, not different types.

Explain what arrays and lists are, using a real-life analogy.

Think about how you organize things at home or in daily life.

Describe the main differences between arrays and lists.

Focus on size and type flexibility.