Відео

Glad it helped!

Congratulations!!! That's awesome!!! You definitely showed that test who was boss with that A*!!!!! Make sure you take time to go celebrate because you deserve it! I am very proud of you!

Great question! You don't need to make a file as they are provided to you in the exam. You will need to make sure you have those files and your electronic paper 4 answer key because that is where you paste your code and screenshots of your program. If you are practicing then you can download the resource files for the exam variant and year or create your own. Let me know if I can help with anything and I will right after the new year. I got a wicked infection right now.

You're welcome! Glad you found it helpful!

The website you got the exam from should have it. Look for the resource files for paper 4. Paper 4 files include the: test, mark scheme and for 9618 resource files which are the .txt files.

You're welcome! Glad you found it helpful!

You're welcome. Glad you found it helpful!

Yes. As loud as possible.

Good afternoon. Unfortunately, that would not be accepted as a simplified expression. There is no XOR gate in this expression so we do not want to add gates that do not exist in the given expression. Can you tell me how you arrived at your answer please so I can clarify further?

Yeah my wife and I are huge Harry Potter fans!

@@erbcomputerscience AWW THAT’S SO COOL IM A BIG POTTERHEAD TOO LOL :D

You're welcome. Glad I was able to help!

You can and can also make the size of the array larger than you need - but only do this if they don't give you the bounds. If they give you the bounds use larger than you may need and that would be fine. For example in question 1 I could have created an array of 100 indices with 3 unused. More often than not they will give you the size.

Do you have any specific questions I may be able to answer?

That's a great question. Some programmers choose to omit index 0. For example if I have a set of dice (say a set of 6) I may want to omit index 0 and start with index 1. This so I know that index 1 relates to dice1 and index 2 dice2 and so on. If I don't omit index 0 I will need to remember that index 4 actually relates to dice5 and index 5 relates to dice4. It all comes down to what a programmer prefers and for me it is all about code that is easy to read and understand. Getting practice with using index 0 and omitting index 0 is the best practice because then you are ready for any scenario. So how do you know which to use? If Cambridge does not give you the lower bound of the array you can use 1 or 0 and it is completely your choice. If Cambridge gives you the lower bound then you have to use what they give 0 - a 0 or a 1. Does that make sense?

Thank you so much

For a traversal of a binary tree they will not give you pseudocode - I would be really surprised if they did. Most of the recursive questions are about traversing the binary tree and binary search and these will not include pseudocode. For other recursive functions, they would most likely give you pseudocode and this is to prevent hundreds of different solutions that they would have to check. No pseudocode for binary tree or binary search. Most likely pseudocode for any others. I did see for example a insertion sort that had to be written recursively and they did give the recursive pseudocode for that.

Yes I do. It can be found here: ua-cam.com/video/GZTVlKDAXuU/v-deo.html

Binary search and traversing a binary tree. All others they will most likely give you pseudocode for.

It could be on P4 but I think it is highly unlikely to be assessed on P4 when it was on P3. I would be ready for it just in case.

Good news! Binary files are not on Paper 4. It is only .txt files that will be assessed on Paper 4.

I have been analyzing the code for a while and found it - it can be traced all the way back to part A. I never declared the 2d array as an integer. If you go back to the 3:25 part of the video you will notice I never declared as an integer which I should have done! When you do not declare the data type, the default data type is an object. What does that matter? Because an Object data type has a value of Nothing as its default value while and integer has a default value of 0. This means the empty nodes would not print out. The empty nodes would not print out because when there is "Empty" or "Nothing" in a reference data type it won't print because nothing is there. If I made it an integer (like I am supposed to) I would have gotten your output. Cambridge never tells us what to declare it as even though it is obvious. Again, I apologize for the typo on my part. Cambridge would take your code. This is from 2021 and over the years they have tightened up their questions making them more clear. This questions was from the very first year of 9618 and was of course written before 9618 happened.

Thank you sir as always!

@@erbcomputerscience Sir could you also please put on a little overtime for us and post that tips and tricks video I asked aswell? Exam's in 3 days so would love to be prepared for the unknown.

@@m1lnhaj Sure. I will do it tomorrow. It will be a good time to go over the Parse/TryParse methods as well as converting to other data types and different ways to do it. I will do it tomorrow and put it up right after I finish. I will send you the link when it goes live.

Ok. It has been done. Here is the video and it goes over Convert, Parse and TryParse and more. Hope you find it helpful! ua-cam.com/video/IMrr2MRQW34/v-deo.html

Because it is in the curriculum it could appear on either Paper 3 or Paper 4. I have not seen any past exam questions where they have assessed a Dictionary so I don't think it could appear. That is just my opinion though. It would be a good idea to know how to program one just in case.

same I have exams in like 14 hours

What are you predicting or expecting for the oct nov exams variant 2

There was a big question of binary tree in p3

So can i think probably no binary tree for p4

I got you covered. I'll be able to record it and post it tomorrow! Any other methods you need me to review? I can add those in the video too.

I believe I couldn't make myself clear. Sir I actually don't know all the methods that we should have an idea about like Parsing was a new thing for me when I came across your walk-through, so these little stuff, hope you get it. So I was wondering if you could cover the methods which you think are necessary to know apart from the obvious?

I was wondering if you could do more question papers maybe before next week Wednesday,that is when the final exam is​@@erbcomputerscience

I am sorry but I have no idea what you are referring to - can you tell me what part of the video you are referring to so I can tell you what it means? I would love to help, I just need to know what part of the video your question is in reference to.

@@erbcomputerscience 1:51:13, the code returns "the item is 999999", im not sure about that part

@@crest1 Ah I see what you are referring to now. The first 6 digits of the item code refer to the item with the 7th digit being a check digit. We enter that into the queue first - 999999X. The check digit(X) is not part of the item code though so only the first 6 digits are. The reason the check digit is X is because the result of the mathematical calculation is 10. We cannot use 10 as the check digit because it is a 7 character string (including the check digit) and not 8. If the item has a valid check digit it is added to the queue and if it is not valid it is not added to the queue and we increment the number of invalid items. When we call Dequeue it outputs the first item that was added to the queue which is the item number 999999. Queues work on the first in first out principle. It removes items in the order they were entered. Because the number 999999X has a check digit of X and is valid, it is the first one outputted from our queue. It is only the item number and not the check digit since just the item number was stored and not the check digit. That is what the substring method does in the video when we do: Result = Input.Substring(0, 6) - It isolates character 0-5 but not character 6 which is the check digit. Remember, when we start counting at 0, 0-6 would be 7 characters, but we just need the item number. The directions say to add the item number to the queue. Our substring starts at 0 and isolates the first 6 characters starting from character 0. 0 1 2 3 4 5 --> 6 Characters total for the substring 9 9 9 9 9 9 -->The item number Does that make sense?

That's a great question. Single and Double take up less memory than Decimal but are less precise which can lead to slight miscalculations. These miscalculations can become very large if data is being processed hundreds or even thousands of times. Remember in 13.3 when you did Mantissa and Exponent? Bits are split between range and precision. Both use fractional binary but are not precise. This is okay if you're doing physics calculations where you only need to go to say 3 significant digits. It's okay that the last few places being held as a decimal are off slightly. When dealing with finances or any program dealing with finances you should use Decimal because it is extremely precise meaning it has higher precision than Single and Double. You definitely do not want a client (or even yourself) to have missing money. Think of a business that is doing thousands of transactions a month. If we are having miscalculations that would lead to lots of money missing throughout the year and it wouldn't match the accounting books at all. Decimal is extremely precise but it is slower than Single and Double and also takes up more memory. In today's world memory isn't really a problem (unless you have a really large program) and speed isn't so much of an issue the way it use to be. For your Cambridge exam it really comes down to choice. I want very high precision so I always use Decimal and tell my students to as well. If you would like to use Single or Double you are more than welcome to, just remember, it doesn't have as high precision as Decimal. Also, Cambridge will give you marks if you have a working solution. In an OOP exercise where they say the data type is REAL, you can use Single, Double or Decimal and they would give you marks for it. Does this help?

@@erbcomputerscience Wow, really appreciate the elaboration sir!

You got it. I have a one more P4 review to do and then I'll do your recursion video with some P3 questions. It'll be sometime this week and I'll get it up as soon as possible for you!

@@erbcomputerscience Thank you but can you please put it up before this wednesday as I would be taking my p3 this wednesday.

@@Hritikesh-p7q A new video before then would be very tough as I have a full day Monday and Tuesday. Here is a video I have that walks through a recursion problem from a past P3 exam that I hope you find helpful. ua-cam.com/video/XuhY2L-5MGo/v-deo.html It walks through a past question as I mentioned which is what you are looking for. Let me know if I can answer any questions for you before your exam if you have any. I would say good luck but you're not going to need it because you got the skills and will crush that P3 and P4 exam!

@@erbcomputerscience Hi thanks Erb.Looking forward for the recursion video.

@@Hritikesh-p7q Here is your recursion video. Hope you find it helpful! ua-cam.com/video/8MWSIE5W1YE/v-deo.html

There's another one in the works and on the way. Should be live in the next couple of days or so.

Here it is: ua-cam.com/video/LawOyp5dnuE/v-deo.html Hope you find it helpful!