Variables & Constants

Test yourself

Variables and Constants

We may need to store data in the memory as part of our program.

The memory

The memory can be thought of as split up into 'blocks' called words.
Each word is usually 32 or 64 bits long.
To access a piece of memory, you have to use its memory address which looks something like 0x9FFF:000F.

Variables

To make life easier for programmers, we can give a memory location a symbolic name called an identifier.
The identifier is a word which describes what we will store in that memory location.
A variable is any part of the memory that we have named, and that we can change the value of while the program is running.

Constants

A constant is a named location in memory that can be used to store a value which does not change while the program is run.

Assignment

The process of setting a value to a variable or a constant is known as assignment.
Assignment is usually shown using an equals sign, e.g:
- height = 39.

1Computational Thinking & Algorithms

1.1Computational Thinking

1.1.1Abstraction Thinking

1.1.2Decomposition Thinking

1.1.3Algorithmic Thinking

1.2Algorithms

1.2.1Algorithms

1.2.2Pseudocode

1.2.3Flow Diagrams

1.2.4Logical Reasoning & Debugging

1.2.5Reading Algorithms

1.2.6Correcting Algorithms

1.2.7Complete the Algorithm

1.2.8Search Algorithms

1.2.9Linear Search

1.2.10Binary Search

1.2.11Sort Algorithms

1.2.12Bubble Sort

1.2.13Insertion Sort

1.2.14End of Topic Test - Algorithms

2Programming

3Hardware & Software

3.1Hardware

3.1.1Elements of Computer Systems

3.1.2Central Processing Unit (CPU)

3.1.3Registers of the Central Processing Unit (CPU)

3.1.4Factors Affecting CPU Performance

3.1.5Fetch-Decode-Execute Cycle

3.1.6Binary Systems

3.1.7Logic Circuits

3.1.8Boolean Logic

3.1.9End of Topic Test - Logic

3.2Software

3.2.1System Software

4Data

4.1Representing Data

4.1.1Binary

4.1.2Converting Binary & Hexadecimal

4.1.3Converting Denary & Hexadecimal

4.1.4Binary Arithmetic

4.1.5Representing Sound

4.1.6Representing Images

4.1.7Character Sets

4.1.8American Standard Code for Information Interchange

4.1.9Unicode

4.1.10End of Topic Test - Representation

5The Internet

5.1Networks

5.1.1Networks

5.1.2Geographical Classification of Networks

5.1.3What is the Internet?

5.1.4The World Wide Web

5.1.5Uniform Resource Locators (URLs)

5.1.6Web Hosting

5.1.7HTML

5.1.8Searching the World Wide Web

5.1.9Good Searching Tips

5.1.10Are You Looking at Reliable Information?

6Online Safety & Security

6.1Protecting Yourself Online

6.1.1Digital Footprints

6.1.2Leaving a Safe Online Footprint

6.1.3Online Safety

6.1.4Malware - Viruses

6.1.5Malware

6.1.6People Online

6.1.7Your Feelings

6.1.8Getting Help

6.2Computing and the Law

6.2.1Data Protection Act (1998)

6.2.2Computer Misuse Act (1990)

6.2.3Freedom of Information Act (2000)

6.2.4Plagiarism

6.2.5Copyright

6.2.6Copyright Designs and Patents Act (1988)

6.2.7Creative Commons Licensing

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