Year 11 - Computing
Dictionary challenge
Programming: dictionaries and data files
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
This unit introduces pupils to the new data structures of records and dictionaries. They will develop a Caesar cipher encryption program using a dictionary as a cipher wheel. Pupils will explore how data can be read from and written to files and how this data can be used within a program.
Lesson Summary
You will learn to create an encryption program using a dictionary with key-value pairs.
Key Notes
- A cipher is a type of secret code, where you swap the letters around so that no one can read your message.
- A Caesar cipher is one of the oldest and most famous ciphers.
- A dictionary data structure can be used to create a Caesar cipher.
- A dictionary maps one thing to another.
Vocabulary To Learn
- encryption: the process of applying an encryption algorithm to plaintext to produce ciphertext that cannot be understood (without decryption)
- key-value pair: when a key (the attribute identifier) is paired with the data
- cipher: an algorithm used to convert plaintext messages to ciphertext (encryption) or ciphertext to plaintext (decryption)
Common Mistakes To Avoid
- A dictionary is a static data structure meaning you cannot add or remove items, only change the values that are available.
3 Quick Questions (With Answers)
1. Describe the system or process from this lesson in clear steps.
A cipher is a type of secret code, where you swap the letters around so that no one can read your message. A Caesar cipher is one of the oldest and most famous ciphers.
2. Define this computing term and give one practical example. 'encryption'
the process of applying an encryption algorithm to plaintext to produce ciphertext that cannot be understood (without decryption). Add one real device or system example to prove understanding.
3. Correct this common computing misconception.
Mistake: A dictionary is a static data structure meaning you cannot add or remove items, only change the values that are available. Correction: A dictionary is a dynamic data structure, which means you can add or remove items in the data structure during program execution.
More Lessons In This Unit
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