2.3.6
Data Structures - 2D Arrays
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2D Arrays
A 2D array is the data structure which consists of an array of arrays.

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

Accessing elements
- To access an individual array, we can access the array as usual:
- array = my2DArray[4]
- To access an individual element, we use this syntax:
- array[5][0]
- This would get the first element of the sixth array.

Applications of 2D arrays
- 2D arrays are often used to represent a 2D surface, for example a chess board:
- Each element of the 2D array could contain the chess piece in that location.
- 2D arrays can be used to represent a database:
- The outer array stores a collection of records.
- The inner arrays store a single record.
1Problem Solving
1.1Algorithms
1.2Decomposition & Abstraction
2Programming
2.1Develop Code
2.2Constructs
2.3Data Types & Structures
2.6Subprograms
3Data
3.2Data Representation
3.3Data Storage & Compression
3.4Encryption
4Computers
4.1Machines & Computational Modelling
4.2Hardware
4.2.1Elements of Computer Systems4.2.2Types of Computer Systems4.2.3Memory - RAM4.2.4Memory - ROM4.2.5Memory - Cache4.2.6Running Out of Memory4.2.7Virtual Memory4.2.8Magnetic Storage4.2.9Properties of Magnetic Media4.2.10Examples of Magnetic Storage4.2.11Solid State Storage4.2.12Properties of Solid State Media4.2.13Optical Storage4.2.14Properties of Optical Storage4.2.15Examples of Optical Storage4.2.16Types of Optical Disk4.2.17Von Neumann Architecture4.2.18Registers of the Central Processing Unit (CPU)4.2.19Fetch-Decode-Execute Cycle4.2.20Factors Affecting CPU Performance4.2.21The Cloud4.2.22How the Cloud Works4.2.23The Cloud - Pros4.2.24The Cloud - Cons4.2.25End of Topic Test - Hardware
4.4Software
5Communication & The Internet
5.1Networks
5.1.1Benefits of Networks5.1.2Network Performance5.1.3Types of Network5.1.4Client-Server Model5.1.5Pros of Client-Server Model5.1.6Cons of Client-Server Model5.1.7Peer-to-Peer Model5.1.8Pros of Peer-to-Peer Model5.1.9Cons of Peer-to-Peer Model5.1.10Network Hardware5.1.11Transmission Media5.1.12WiFi5.1.13WiFi Frequency and Channels5.1.14WiFi Encryption5.1.15Network Protocols5.1.16Transmission Protocols5.1.17Web Protocols5.1.18Email Protocols5.1.19Layers5.1.20TCP and OSI Models5.1.21Advantages of Layering5.1.22Topology - Star5.1.23Topology - Mesh5.1.24Topology - Ring5.1.25Topology - Bus5.1.26End of Topic Test - Networks
5.2Network Security
6The Bigger Picture
6.1Emerging Trends, Issues & Impact
6.1.1E-Waste6.1.2Energy Consumption6.1.3Positive Environmental Impact6.1.4Ethical Issues - The Digital Divide6.1.5Ethical Issues - Net Neutrality6.1.6Ethical Issues - Working Conditions6.1.7Ethical Issues - Censorship6.1.8Online Activity Tracking6.1.9The Internet of Things6.1.10Positive Cultural Impacts6.1.11Negative Cultural Impacts6.1.12Data Protection Act6.1.13Computer Misuse Act6.1.14Copyright Designs and Parents Act6.1.15Creative Commons Licensing6.1.16Freedom of Information Act6.1.17Open Source Software6.1.18Proprietary Software6.1.19Licensing Issues6.1.20End of Topic Test - Software & Issues
Jump to other topics
1Problem Solving
1.1Algorithms
1.2Decomposition & Abstraction
2Programming
2.1Develop Code
2.2Constructs
2.3Data Types & Structures
2.6Subprograms
3Data
3.2Data Representation
3.3Data Storage & Compression
3.4Encryption
4Computers
4.1Machines & Computational Modelling
4.2Hardware
4.2.1Elements of Computer Systems4.2.2Types of Computer Systems4.2.3Memory - RAM4.2.4Memory - ROM4.2.5Memory - Cache4.2.6Running Out of Memory4.2.7Virtual Memory4.2.8Magnetic Storage4.2.9Properties of Magnetic Media4.2.10Examples of Magnetic Storage4.2.11Solid State Storage4.2.12Properties of Solid State Media4.2.13Optical Storage4.2.14Properties of Optical Storage4.2.15Examples of Optical Storage4.2.16Types of Optical Disk4.2.17Von Neumann Architecture4.2.18Registers of the Central Processing Unit (CPU)4.2.19Fetch-Decode-Execute Cycle4.2.20Factors Affecting CPU Performance4.2.21The Cloud4.2.22How the Cloud Works4.2.23The Cloud - Pros4.2.24The Cloud - Cons4.2.25End of Topic Test - Hardware
4.4Software
5Communication & The Internet
5.1Networks
5.1.1Benefits of Networks5.1.2Network Performance5.1.3Types of Network5.1.4Client-Server Model5.1.5Pros of Client-Server Model5.1.6Cons of Client-Server Model5.1.7Peer-to-Peer Model5.1.8Pros of Peer-to-Peer Model5.1.9Cons of Peer-to-Peer Model5.1.10Network Hardware5.1.11Transmission Media5.1.12WiFi5.1.13WiFi Frequency and Channels5.1.14WiFi Encryption5.1.15Network Protocols5.1.16Transmission Protocols5.1.17Web Protocols5.1.18Email Protocols5.1.19Layers5.1.20TCP and OSI Models5.1.21Advantages of Layering5.1.22Topology - Star5.1.23Topology - Mesh5.1.24Topology - Ring5.1.25Topology - Bus5.1.26End of Topic Test - Networks
5.2Network Security
6The Bigger Picture
6.1Emerging Trends, Issues & Impact
6.1.1E-Waste6.1.2Energy Consumption6.1.3Positive Environmental Impact6.1.4Ethical Issues - The Digital Divide6.1.5Ethical Issues - Net Neutrality6.1.6Ethical Issues - Working Conditions6.1.7Ethical Issues - Censorship6.1.8Online Activity Tracking6.1.9The Internet of Things6.1.10Positive Cultural Impacts6.1.11Negative Cultural Impacts6.1.12Data Protection Act6.1.13Computer Misuse Act6.1.14Copyright Designs and Parents Act6.1.15Creative Commons Licensing6.1.16Freedom of Information Act6.1.17Open Source Software6.1.18Proprietary Software6.1.19Licensing Issues6.1.20End of Topic Test - Software & Issues
Practice questions on Data Structures - 2D Arrays
Can you answer these? Test yourself with free interactive practice on Seneca — used by over 10 million students.
- 1What would the command "array[5][3] = 0" do to a 2D array?Multiple choice
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