Search CSNewbs

Homepage for learning about computer science in school. Discover topics across GCSE and Level 3 IT subjects, plus programming languages including Python, HTML and Greenfoot. C omputer S cience P ros Official 2026 CSPros: Henry C Rohan Finlay Adam Chantel Olivia Jessie Kelvin Lucas Gajanan Danny Marcus José Claudia Charlie Ryan Harry Ethan Henry P Yash Marcus Thomas Walter Folu Asher Pippa Zach Leighton Jess James Holly Zac Ryan 2025 CSPros: Jack Harry Aarav Trisha Mario Hiba Rory Clark Lucy Divya Luke Callum James Zoya Timucin Matthew 2024 CSPros: 2023 CSPros: Henry Zain Iman Alex I-C Alex B Tomos Aidan Rahul Hussain Diyar Sam Harry Will Alex H 2022 CSPros: Logan Eleanor Mark Edward Alfie Henry Enzo Sam George Harry Ella Kav

Learn about algorithms including pseudocode and flowcharts. Based on the 2020 Eduqas (WJEC) GCSE specification. 8.2: Understanding Algorithms Exam Board: Eduqas Specification: 2020 What is an algorithm? An algorithm is a set of instructions , presented in a logical sequence . In an exam you may be asked to read and understand an algorithm that has been written. To prove your understanding you may be asked to respond by actions such as listing the outputs of the algorithm, correcting errors or identifying an error within it. Programmers create algorithm designs as a method of planning a program before writing any code. This helps them to consider the potential problems of the program and makes it easier to start creating source code. There are two main methods of defining algorithms : Defining Algorithms - Pseudocode & Flowcharts Pseudocode Pseudocode is not a specific programming language but a more general method of describing instructions . It should be unambiguous, and it should not resemble any particular kind of programming language (e.g. Python or Java), so it can theoretically be turned into working code in any language. Generally, pseudocode can be written in any way that is readable and clearly shows its purpose. However, the Eduqas exam board advises that pseudocode for the programming exam should follow the conventions below : Annotation { Write your comment in curly brackets} Define data type price is integer firstname is string Declare a variable's value set price = 100 set firstname = "Marcella" Input / output output "Please enter your first name" input firstname Selection (must have indentation) if firstname = "Steven" then output "Hello" + firstname elif firstname = "Steve" then output "Please use full name" else output "Who are you?" end if Iteration (while loop) while firstname ! = "Steven" output "Guess my name." input firstname repeat Iteration (for loop) for i in range 10 input item next i Define a subroutine Declare Sub1 [Subroutine content indented] End Sub1 Call a subroutine call Sub1 Flowcharts A flowchart can be used to visually represent an algorithm. The flowchart symbols are: Algorithm Examples Below are two different methods for representing the same algorithm - a program to encourage people to buy items cheaply at a supermarket. The program allows the price of items in a supermarket to be entered until the total reaches 100. The total price and the number of items entered are tracked as the program loops. Once the total reaches 100 or more, an if statement checks how many items have been entered and a different message is printed if there are 20 or more items, 30 or more items or less than 20 items. Pseudocode Flowchart {This is a program to see how many items you can buy in a supermarket before you spend over £100} total is integer, itemsentered is integer, itemprice is integer set total = 0 set itemsentered = 0 while total < 100 output "enter the price of the next item" input itemprice total = total + itemprice itemsentered = itemsentered + 1 repeat if itemsentered >= 20 then output "You are on your way to saving money." elif itemsentered => 30 then output "You're a real money saver." else output "Look for better deals next time." end if Reading Algorithms In an exam you may be asked to read an algorithm and prove your understanding , most commonly by listing the outputs . Start from the first line and follow the program line by line , recording the value of variables as you go . When you encounter a for loop , repeat the indented code as many times as stated in the range . Example Algorithm: Start NewProgram i is integer maxvalue is integer input maxvalue for i = 1 to maxvalue output (i * i) ??????? output 'program finished' End NewProgram Example Questions: 1. List the outputs produced by the algorithm if the 'maxvalue' input is 5 . 2. State the code that has been replaced by '???????' and what the code's purpose is. Example Answers: 1. Outputs: 1 4 9 16 25 program finished 2. Missing Code: next i Purpose: Moves the loop to the next iteration. Watch on YouTube Q uesto's Q uestions 8.2 - Understanding Algorithms: 1a. Read the algorithm shown on the left and list all outputs in the correct order if the inputs are 2 for height and 72 for weight . 1b. Give the code that is missing from line 25 . 8.1 - Programming Principles Theory Topics 8.3 - Writing Algorithms

Learn about the components of the Central Processing Unit (CPU) and Von Neumann architecture. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). Exam Board: OCR 1.1a: The CPU Specification: J277 Watch on YouTube : Purpose of the CPU CPU Components Von Neumann Architecture The Central Processing Unit ( CPU ) is the most important component in any computer system. Like many computer components, it is attached to the motherboard . The purpose of the CPU is to process data and instructions by constantly repeating the fetch-execute cycle . CPU Components The Control Unit (CU ) sends control signals to direct the operation of the CPU . Control signals and timing signals are sent to the ALU and other components such as RAM . It also decodes instructions as part of the fetch-execute cycle . ALU stands for ‘ Arithmetic and Logic Unit ’. It performs simple calculations and logical operations . A register is a temporary storage space for one instruction or address . Different registers are used during the fetch-execute cycle . Cache memory is used to temporarily store data that is frequently accessed . Cache memory is split into different levels . Cache is slower to access than the registers but much faster than RAM . Computer Architecture The way a computer is designed and structured is known as its architecture . The most common type of computer architecture is Von Neumann . It is named after the mathematician John Von Neumann (pronounced Von Noy-man) Von Neumann Architecture A computer with Von Neumann architecture stores both program instructions and data in the same memory (RAM ) and in the same format (in binary ). Instructions (technically called the opcode ) and data (technically called the operand ) are not the same . An instruction is an action to perform and data is the value to be used. For example with the command 'ADD 43 ', ADD is the instruction and 43 is the data . Von Neumann architecture also contains the key CPU components of a control unit , arithmetic logic unit (ALU ), registers and cache memory . Q uesto's Q uestions 1.1a - The CPU: 1a. What does 'CPU ' stand for ? [1 ] 1b. What is the purpose of the CPU ? [ 2 ] 2. Draw a diagram of the CPU , and l abel the four main components . [ 4 ] 3. Describe the purpose of: a. The Control Unit [ 2 ] b. The ALU [ 2 ] c. The registers [ 2 ] d. Cache memory [ 2 ] 4a. Describe the key feature of Von Neumann architecture . [ 2 ] 4b. Explain how an instruction is different to data . [ 2 ] 1.1b - Registers & FE Cycle Theory Topics

Learn about operating systems, memory management (segmentation and paging), scheduling, interrupts, the BIOS, device drivers and virtual machines Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 2.1 - Systems Software Specification: Computer Science H446 Watch on YouTube : Operating systems functions Paging & segmentation Interrupts Scheduling algorithms Types of operating system BIOS Device drivers Virtual machines This topic looks at how the operating system manages the resources of a computer system . It also includes programs related to the operating system , such as the BIOS , device drivers and virtual machines . Operating Systems The operating system performs essential functions to keep a computer running efficiently . It provides a user interface , such as a command line or graphical user interface ( GUI ), and ensures system security by managing access rights and protecting files . The OS manages hardware , coordinating devices like the CPU , printers and hard drives and provides built-in utilities for tasks such as file management and disk defragmentation . It acts as a platform for software , allowing applications to be installed and run . The OS also schedules jobs , handles interrupts from devices, and manages memory , ensuring each process has the resources it needs without conflicts. Paging & Segmentation Paging is a memory management method that splits memory into equal-sized blocks called pages . This makes memory use more efficient as programs don’t need to be stored in one continuous block but unused space may be wasted inside a page . Segmentation divides memory into segments of different sizes based on program structure . This makes it easier to organise parts of a program , but because segments are different sizes , it can leave small unused gaps in memory that can’t be easily filled by other data. Interrupts An interrupt is a signal that tells the CPU to pause its current task and respond to something more urgent . Interrupts can come from hardware , such as a keyboard press , or from software , such as an error . When an interrupt occurs , the CPU saves its current state by placing current register values into a stack . The CPU runs an interrupt service routine ( ISR ) to handle the interrupt event . After the ISR finishes , the CPU restores its state by popping values from the stack and continues the original program . Scheduling Scheduling algorithms are used by the CPU to decide the order in which processes are executed . They aim to manage CPU time efficiently and ensure all programs get a fair share of resources . Common scheduling algorithms include: First-Come First-Served : Processes are executed in the order they arrive to the CPU . Round Robin : Each process gets a fixed time slice in turn , cycling through all processes. Shortest Job First / Shortest Time Remaining : These methods identify the process with the shortest estimated runtime to be executed first . Multi-Level Feedback Queue : Uses multiple queues with different priority levels . Processes can be moved between queues to avoid starvation . Types of OS Different types of operating systems exist depending on the computer system and purpose : Multitasking OS : Allows a single computer to run multiple programs at the same time by quickly switching between them. Multi-user OS : Lets multiple users access the computer and its resources simultaneously , often via a network . Distributed OS : Manages a group of networked computers as a single system , sharing resources and tasks . Embedded OS : Designed for devices with specific functions , like microwaves or smart TVs , often with limited resources . Real-time OS : Provides immediate processing and responses for time-critical tasks , used in systems like medical devices or industrial robots . The BIOS The BIOS (Basic Input/Output System ) is firmware stored in ROM that helps the computer start up and manage initial communication between hardware and the operating system . During the start-up sequence , the BIOS first checks that essential hardware (e.g. the CPU and RAM ) is present and working correctly by running a Power-On Self Test (POST ). Signals are transmitted to all connected components . The BIOS then runs the bootstrap program to locate and load the operating system from a connected storage device into RAM . Once the OS is loaded , control is handed over to it, allowing the computer to become fully operational . Device Drivers A device driver is software that allows the operating system to communicate with hardware devices such as printers , graphics cards or keyboards . Hardware and the OS speak different ' languages ', so the driver translates OS instructions into commands the device can understand and vice versa. They are needed because, without drivers , the OS wouldn’t know how to control the hardware or use its features properly. Drivers also allow devices to work with different versions of an operating system and enable updates that improve performance or fix bugs . Virtual Machines A virtual machine is a software-based computer that runs an operating system and applications like a real computer , using part of the host computer’s hardware . It is isolated from the main system , so it can operate safely without affecting the host . Virtual machines are commonly used for testing software , running multiple operating systems and safely handling untrusted files . They provide flexibility , efficient hardware use and a secure environment for experimentation . Q uesto's K ey T erms Operating Systems: user interface, file management, user management Memory Management: paging, segmentation, virtual memory Interrupts: interrupt, interrupt service routine, stack Scheduling Algorithms: first come first serve, round robin, shortest job first, shortest time remaining, multilevel feedback queue Types of Operating System: multitasking, multi-user, distributed, embedded, real-time BIOS: ROM - power-on self-test (POST) Device Drivers: device driver Virtual Machines: virtual machine, thin clients, servers D id Y ou K now? New versions of the Android operating system used to be named alphabetically after sweet treats , from Cupcake , Donut and Eclair to Nougat , Oreo and Pie - the final named update in 2019 . 1.3 - Input, Output & Storage A-Level Topics 2.2 - Applications Generation

Learn about the different types of organisations that hold information. Also, consider the differences between urban and rural connections and remote locations. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2. 1.1 - Holders of Information Exam Board: OCR Specification: 2016 - Unit 2 Categories of Information Holders Organisations that store and process information can be put into seven different categories : Business A business will hold information on all of its employees , including their date of birth, address and financial information , allowing them to be paid at the end of each month. Businesses will also hold commercial information about their organisation such as profits and losses, product descriptions and historical data . Many companies may record information about their competitors and general marketing data. Government The government will hold a huge amount of information about all citizens in the country including financial earnings, tax paid, births and deaths . The electoral roll holds information about addresses . A national census is taken every 10 years in the UK (the next census is in 2021) that records extensive data about everyone living in the country. The government also stores information about other countries and shares some of this publicly, such as the Foreign Office posting travel advice . Individual Education Educational organisations , such as schools, colleges and universities will hold information about current and past students as well as staff. Student information such as addresses, attendance records and examination history will be recorded, as well as contact information for parents and guardians. Teacher information will be stored too, as well as students that previously attended the institution, even for a number of years after they have left. An individual will hold information about themselves , either in their head or on paper or electronically. This includes their name, date of birth, address, usernames and passwords . Individuals will store information of others , such as phone numbers, social media details and email addresses . Other information will be about organisations , such as the address of their favourite restaurant, opening hours of the local cinema or the telephone number from a catchy advert. Healthcare Healthcare services , like the NHS in the United Kingdom, will hold entire medical histories for each civilian in the country. This includes basic personal information such as current address and date of birth but much more detailed data too like previous illnesses and operations, blood type, allergies and prescriptions . The data stored by healthcare organisations is usually confidential and should not be shared by anyone other than the citizen in question. Charity & Community Charities may hold financial information of donors who give money to them, as well as information about the different projects that the donations are funding. Charities such as the British Heart Foundation might have physical addresses on the high street so information may be kept about the shops too. Community organisations like sport centres or religious institutions may hold information on members and matches, meetings or events . Comparison of Locations The location of systems and data affects access speed and network quality . The digital divide is the gap between people who do and do not have easy access to computers and networks . Developed vs. Developing Countries Developed countries , like areas of Western Europe, North America and East Asia, have a more developed technology and industry base with more funding available for information infrastructures such as cabling and high-speed access . Developing countries , like areas of Africa and Central Asia, have unstable governments and slower access (if any) to the internet . Less money is spent on technology and improving broadband speed and expensive equipment like computers cannot be purchased on low wages . Urban vs. Rural Urban locations like towns and cities have a high population density . Because there are so many people, councils and IT companies will spend a lot of money on internet infrastructure such as cabling and installing high-speed lines . In Rural locations like the countryside, the population is sparse and settlements may be far apart so internet access is poorer and broadband speeds are slower . This means accessing information on the internet is more difficult . Internet Access from Remote Locations Remote locations (such as the countryside or difficult-to-reach areas like mountains or deserts) might have limited internet access . Fast fixed broadband is expensive to install and many providers simply won't invest in rural areas as it is not economically viable . Some areas, usually those with a very small or temporary population, might have no fixed internet access which will make it difficult for an individual or organisation to communicate or work online. Many remote locations have some form of internet but download speeds will be slow or interrupted due to intermittent connection . This makes it difficult to work online and could take a long time to access webpages or document stores. Alternatives to fixed broadband in remote locations include mobile broadband and satellite broadband . Mobile broadband is generally not designed for home use and would be very expensive for everyday use , plus the remote location will generally mean mobile coverage could also be weak . Satellite broadband requires a dish with an unrestricted view of the sky. Satellite broadband has a relatively high internet speed but will cost a lot to install and has a high latency (more chance of experiencing lag). Q uesto's Q uestions 1.1 - Holders of Information: 1a. State the 7 categories of information holders . [7 ] 1b. For each of the 7 categories , briefly describe 3 different pieces of information that may be stored by the information holder. For example, a charity may store the financial information of donors. [3 each ] 2. What is the digital divide ? [2 ] 3. Describe the differences in information access for the following locations : a. Developed vs. developing countries b. Urban vs. rural areas c. Remote locations [4 each ] Topic List 1.2 - Storage Media

Learn about troubleshooting tests and information to record when a hardware error occurs. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 1.6 - Hardware Troubleshooting Exam Board: OCR Specification: 2016 - Unit 1 What is troubleshooting? Troubleshooting means to analyse and solve a problem with a computer system. Hardware troubleshooting refers to fixing an issue with the physical parts of the computer or any connected devices. Hardware issues might occur as a result of damage (intentional or accidental), power surges or malware . Steps to Take When an Error Occurs Try to identify the problem by looking for the simplest explanation first (e.g. checking the power supply) and ask the user questions about the issue. Create a theory about what the cause of the problem could be and prepare to test the theory using a series of troubleshooting tests . Create a troubleshooting plan and record the steps that are taken before moving on to the next test. Check the system works after each stage of the plan. Create a findings document that explains if and how the problem was fixed, for future reference if the problem occurs again. Documentation Technicians and help desk (see 3.5 ) staff should document , on a fault sheet , the following information regarding the issue: The fault itself (such as 'system not turning on'). The system in question. The user logged in at the time. Exact date & time the problem occurred. Symptoms of the issue (such as 'slow load times' or 'beeping'). Problem history - checking if it has happened to this system before. Back up documentation - Whether the data been backed up recently. Troubleshooting Tools The following tools can be used to identify an error so a technician has a greater understanding of the problem. Event Viewer Event Viewer is a type of utility software that lists detailed information about an error when one occurs. It can be used to work out how to fix the issue and will display both minor and major faults. Power On Self Test (POST) On start-up, a power on self test (POST) checks memory, power, hardware and cooling systems are all working properly. Beep codes signal if an error has been detected; 1 beep will sound for no error but if multiple beeps are heard then an error has been discovered. Ping Test This is a connectivity test between two computers. A message is sent to the destination computer and waits for a return message named the echo reply . This procedure can be repeated with other systems until the source of the problem is identified from a computer that does not reply . Q uesto's Q uestions 1.6 - Hardware Troubleshooting: 1. Summarise the 'Steps to Take when an Error Occurs ' section into your own top three tips for what to do when a hardware error happens . [3 ] 2. List 6 pieces of information that an IT technician should record when a hardware error has occurred . [6 ] 3. Briefly explain the purpose of three troubleshooting tools . [6 ] 1.5 - Communication Hardware 1.7 - Units of Measurement Topic List

Learn about policies related to application development, including a user guide, acceptable use policy (AUP), backup, codes of practice, staying safe online and the use of information. Resources based on Unit F161 (Developing Application Software) for the OCR Cambridge Advanced Nationals in Computing (H029 / H129) AAQ (Alternative Academic Qualification). Qualification: Cambridge Advanced Nationals in Computing (AAQ) Certificate: Computing: Application Development (H029 / H129) Unit: F161: Developing Application Software 5.3 - Policies Watch on YouTube : Policies You need to know the purpose , content and application of each policy to be considered when related to developing application platforms . What You Need to Know Policies ? YouTube video uploading soon Q uesto's Q uestions 5.3 - Policies: 1. What? [2 ] 2. What? [1 ] 3. What? [1 ] 4. What? [1 ] ? D id Y ou K now? 5.2 - Application Installation Topic List 6.1 - Legal Considerations

Learn about the importance of planning application development projects, including the advantages and disadvantages of planning and the consequences of not planning. Also covers planning considerations such as budget, time, resources, success criteria and legislation. Based on Unit F160 (Fundamentals of Application Development) for the OCR Cambridge Advanced National in Computing (H029 / H129) (AAQ - Alternative Academic Qualification). Qualification: Cambridge Advanced National in Computing (AAQ) Unit: F160: Fundamentals of Application Development Certificate: Computing: Application Development (H029 / H129) 3.1 - Planning Projects Watch on YouTube : Purpose of Planning Planning Considerations Planning Projects You need to know why it is important to plan an application development project , as well as the advantages and disadvantages of taking the time to plan . You must also consider the potential consequences if a development team decide not to plan their project. There are several considerations (e.g. budget , time and legislation ) that must be looked at in the planning stage and you need to know how these may impact application development . You need to be aware of copyright , data protection and electronic communication legislation , but for this unit , you do not need to know the details of any specific laws . Importance of Planning Projects Planning application development projects is important as it sets clear goals and direction for the project and identifies required resources (e.g. time , money , people and tools ). Other advantages include better organisation , as team members should know their roles and tasks . Also, planning improves time management as deadlines and milestones keep the project on track . However, there are disadvantages to planning as it takes time and can delay the start of development . Also, plans may become outdated if requirements unexpectedly change mid-project . Avoiding planning entirely will have consequences , such as a higher potential for missed deadlines and overrunning costs due to poor time / budget estimates . Goals may be unclear , leading to confusion , delays or an unusable product . Planning Considerations There are several considerations team members must carefully evaluate in the planning phase of application software development : The three types of legislation cover copyright , data protection and electronic communication . Q uesto's Q uestions 3.1 - Planning Projects: 1. A company developing smartphones is considering whether to skip the planning stage and move straight to design. Give two advantages and two disadvantages of planning and two consequences of not planning an application development project . [6 ] 2. Summarise the impact of the three identified types of legislation on application development . [6 ] 3. Justify which planning consideration you think has the biggest potential impact on the success of a software application development project and why . [ 3 ] 4. Describe the impact of three planning considerations (other than legislation and the one you chose in Q3 ) on application development . [6 ] If a company seriously breaches the Data Protection Act , it can be fined up to £17.5 million or 4% of its global turnover , whichever is higher . D id Y ou K now? 2.2 - Phases of Development Models Topic List 3.2 - Project Planning Tools

Test your ability to create a more complex program in Python based on a given scenario. Perfect for students learning GCSE Computer Science in UK schools. Extended Task 2 Lottery 17 8 4 13 20 Create a program to simulate a lottery draw. First, create an appropriate print line to welcome the user to your lottery draw. Then let the user enter five numbers between 1 and 20. Next, randomise five numbers between 1 and 20. Check to see how many numbers match and output an appropriate response for each scenario (e.g. “You have not matched any numbers, better luck next time!”) Once you have made the base program implement subroutines and lists . Make it as efficient as possible and professional-looking. Use pauses to reveal each number one at a time like a real lottery draw to build suspense. For this task, you will need to create a document and include the following sections (with screenshots where appropriate): An introduction to explain the Purpose of your program . A List of Requirements for a successful program. Screenshots of your code (with comments in your code to show understanding). Testing – Create a plan to show how you will test your program and then explanations of any errors that you found and how they were fixed . An Evaluation of what worked, what didn’t, and how you met each of your requirements from your original list. Also, discuss further improvements that you could have made to improve your program. Example solution: Helpful reminders for this task: Inputting Numbers Random Numbers Logical Operators Subroutines ⬅ Extended Task 1 (Pork Pies) Extended Task 3 (Blackjack) ➡

Learn about the benefits of compression and the differences between lossy and lossless compression. Also, learn how compression ratios work. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 2.5: Compression Exam Board: OCR Specification: J277 Watch on YouTube : Compression Benefits Lossy Compression Lossless Compression What is compression? To compress a file means to make its size smaller . Benefits of compression include: Files take up less storage space (so more files can be stored). Files can be transferred quicker (because they are smaller). Files can be read from or written to quicker . There are two methods that are used to compress files: Lossy and Lossless . Lossy Compression Lossy compression uses an algorithm (set of instructions) to analyse a file and remove data that cannot be heard or seen by humans . For example, a lossy algorithm would analyse the sound waves of an audio file and remove any frequencies which humans cannot hear. This process reduces the size of the file . Further lossy compression will remove data that humans can see / hear . For example, the dog image to the right has been strongly compressed using a lossy algorithm and some data has clearly been removed. Lossy compression removes the data permanently , so the file can never return to its original form . Lossy compression is often used with images , audio and video to reduce the file size, for example to send over the internet. Lossless Compression Lossless compression reduces the size of a file without permanently removing any data . Because of this, the file is returned to its original form when decompressed, so no quality is lost . A file that is compressed with a lossless algorithm is usually larger than a file compressed with a lossy algorithm because no data has been permanently removed. Lossless compression is used with files that would not function properly if data were permanently removed, such as executable files (e.g., programs and games) or word documents . Remember that lossy and lossless compression do not just refer to images. Below is an audio file that has been compressed with lossy compression . Data has been removed so the audio quality has decreased. 197 KB 81 KB 43 KB Q uesto's Q uestions 2.5 - Compression: 1. Describe 3 benefits of compressing a file . [ 3 ] 2. Describe the differences between lossy and lossless compression . [4 ] 3. A student needs to compress a Microsoft Word document to send in an email. Suggest which type of compression they should use and why . [ 2 ] 2.4e Sound Storage Theory Topics 3.1a - Network Types & Performance

Learn how to comment in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 1b - Commenting Writing Comments To annotate your work, you can write a comment using the # symbol. Comments are ignored when you run the program and they are not printed . #This is a comment! print ( "Welcome to Python!" ) #The code above prints a nice greeting = Welcome to Python! Programmers use comments to explain to other people (and themselves) what different sections of code do . With massive programs, comments are vital; otherwise, it would be too confusing, especially after returning from a few weeks or months on a different project. If you are creating a Python project for school (or A-Level Computer Science coursework), you will need comments to explain your code and prove you have written it yourself. Comments over Multiple Lines Have a lot to say in one comment? Use three apostrophes ( ”’ ) at the start and three more at the end of your comment like below: '''This is a comment that I have spread out over more than one line''' print ( "Hello! How are you?" ) Top Tip: Use multi-line comments when testing a program to ‘blank out’ sections that you know work fine and only focus on one part at a time. Commenting Task 1 (Day of the Week & Weather) On line 1 write a single-line comment ( use # ) to state that your program will print the day of the week. On line 2 print the current day of the week. On lines 3, 4 and 5 write a multi-line comment (use ''' ) about the weather today. Remember comments won't be printed so only the day of the week should be output. Example solution: Wednesday ⬅ 1a - Pri nting 1c - Crea ting Variables ➡

The most common errors made in Grennfoot when making a game and how to fix them, including when missing punctuation is expected or the end of file is reached while parsing. Common Greenfoot Errors Greenfoot Home If the world becomes greyed out and you can't click on anything then an error has occurred. The actor with the error will have red lines on it. When an error occurs, a red squiggly line will appear underneath the problem. Hover your mouse over the line and a helpful message will appear to help you solve the issue. Some of the more common errors (and how to fix them) are listed below: ; expected Every line with a white background must end in a semi colon ( ; ) ) expected You have missed a bracket . Count the number of open brackets and the number of closed brackets on a line and make sure you have an equal number of both. reached end of file while parsing You are missing at least one curly bracket ( } ) at the end of your program . Press enter to move onto a new line at the bottom; you must have a closed curly bracket with a yellow background and another closed curly bracket with a green background . cannot find symbol You have typed a command incorrectly . Greenfoot uses a system where commands have no spaces and each word after the first word is uppercase . Such as isKeyDown not IsKeyDown and not isKeydown. Check your spelling and capitals carefully. Stuck ? If you start typing but can't remember what commands come next, press Ctrl and Space together to show a list of all possible commands that you can use.