2.1.17
2D Lists
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2D Lists
A 2D list is the data structure which consists of a list of lists.

2D List
- A 2D list is a data structure where lists are filled with other lists.
- This can be used to represent a 2D surface, or records.

Accessing elements
- To access an individual list we can access the list as usual:
- list = my2DList[4]
- To access an individual element, we use this syntax:
- list[5][0]
- This would get the first element ([0]), of the sixth list ([5]).

Uses of 2D lists
- 2D lists are often used to represent a 2D surface, for example a chess board:
- Each element of the 2D list could contain the chess piece in that location.
- 2D lists can be used to represent a database:
- Each inner list can store a record of the database.
- The outer list can store each record.
1Computational Thinking & Algorithms
1.1Computational Thinking
1.2Algorithms
1.2.1Algorithms1.2.2Pseudocode1.2.3Flow Diagrams1.2.4Logical Reasoning & Debugging1.2.5Reading Algorithms1.2.6Correcting Algorithms1.2.7Complete the Algorithm1.2.8Search Algorithms1.2.9Linear Search1.2.10Binary Search1.2.11Sort Algorithms1.2.12Bubble Sort1.2.13Insertion Sort1.2.14End of Topic Test - Algorithms
2Programming
2.1Programming Fundamentals
2.1.1Variables & Constants2.1.2Comments2.1.3Input & Output2.1.4Arithmetic Operators2.1.5Relational Operators2.1.6Boolean Operators2.1.7Sequence2.1.8Selection2.1.9Iteration2.1.10Subroutines2.1.11Scope2.1.12Data Types2.1.13Casting2.1.14Arrays2.1.152D Arrays2.1.16Lists2.1.172D Lists2.1.18Strings2.1.19Syntax Errors2.1.20Logic Errors2.1.21Runtime Errors2.1.22End of Topic Test - Programming
2.2Designing Code
3Hardware & Software
3.1Hardware
3.2Software
4Data
5The Internet
6Online Safety & Security
6.1Protecting Yourself Online
Jump to other topics
1Computational Thinking & Algorithms
1.1Computational Thinking
1.2Algorithms
1.2.1Algorithms1.2.2Pseudocode1.2.3Flow Diagrams1.2.4Logical Reasoning & Debugging1.2.5Reading Algorithms1.2.6Correcting Algorithms1.2.7Complete the Algorithm1.2.8Search Algorithms1.2.9Linear Search1.2.10Binary Search1.2.11Sort Algorithms1.2.12Bubble Sort1.2.13Insertion Sort1.2.14End of Topic Test - Algorithms
2Programming
2.1Programming Fundamentals
2.1.1Variables & Constants2.1.2Comments2.1.3Input & Output2.1.4Arithmetic Operators2.1.5Relational Operators2.1.6Boolean Operators2.1.7Sequence2.1.8Selection2.1.9Iteration2.1.10Subroutines2.1.11Scope2.1.12Data Types2.1.13Casting2.1.14Arrays2.1.152D Arrays2.1.16Lists2.1.172D Lists2.1.18Strings2.1.19Syntax Errors2.1.20Logic Errors2.1.21Runtime Errors2.1.22End of Topic Test - Programming
2.2Designing Code
3Hardware & Software
3.1Hardware
3.2Software
4Data
5The Internet
6Online Safety & Security
6.1Protecting Yourself Online
Practice questions on 2D Lists
Can you answer these? Test yourself with free interactive practice on Seneca — used by over 10 million students.
- 1What would the command list[5].append(3) do to a 2D list?Multiple choice
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