Linear Search- This searches a list of numbers to find out which position a certain number is in the list. It searches every number in the list until the number indicated is found. After this is achieved the loop finishes and the number’s position is displayed.
Example- if current-number = search-number then
position = current-item position
Count Occurrences- This standard algorithm searches a list of numbers one by one and counts how many times said number appears then outputs the result. It uses a counter and every time the given number is found 1 is added to the counter.
Example- if current_number = occurrences_number then
counter = counter + 1
equence, Selection and Iteration:
Sequence– Every line of code is executed in order from top to bottom.
Selection– The program can make decisions, using THEN…ELSE…IF
Iteration– Basically an up-market way to describe repeat. It allows our program to do things over and over again.
The 7 Characteristics of a completed program:
- Correct – Ensures the completed program meets the software specification
- Maintainable – Means that you are able to alter it and correct bugs easily
- Reliable – Will always give the correct answer every time no matter what. eg if it was asked 5+3 a million times it would output 8 a million times
- Readable – The program makes use of white spaces, utilizes internal commentary and also uses relevant names for variables
- Portable – Has the versatility to run on any type of computer
- Efficient – Doesn’t slow down the computers performance in anyway. eg. by using too much memory
- Robust – Will keep working no matter what is thrown at it
The 3 types of programming language:
- Procedural – Has an obvious start and end point and it’s sequence is specified by the programmer
- Declarative – At the beginning the programmer declares everything, queries can be used to solve problems
- Event-Driven – Permits the user to make the Human-Computer-Interface, things in the program are activated from the user pressing a button etc
High Level vs Low Level Language:
Programming languages that are generally written in English and use words such as IF, ELSE, REPEAT are known as High Level Languages, it is worth noting that computers do not actually understand this kind of language. However computers do understand binary codes (machine codes), this is known as a Low Level Language.
A Data Dictionary is a document which lists all of the fields of a database and stores things about them, such as validation, the amount of characters it requires and whether it is a primary or foreign key.
An Entity Relationship Diagram is a graphical representation of all the entities in a database which shows their relationships with each other. There are three types of relationships entities can have, these are one to one, one to many and many to many.
I have learned that there are four main file formats which can be used to store a bitmapped graphics:
- Bitmap (BMP)
- Graphic Interchange Format (GIF)
- Joint Pictures Expert Group (JPEG)
- Portable Network Graphics (PNG)
I have also learned that bitmapped graphics can be compressed, this may reduce the image quality but it also reduces the image size which makes it easier for people to share their graphics through email etc.
Von Neumann Architecture
This is a design architecture for a computer processor; it’s subdivisions are Main memory, Output Devices, Input Devices and Backing Storage.
A Control Bus is used for the computer to communicate with other devices within the computer; it is the idea that there are many shoe boxes with different addresses.
The Arithmetic Logic Unit (ALU) is a digital circuit which performs operations within the computer.
A Bus transfers data in a computer, there are many buses such as:
The Address Bus, carries information from the processor to main memory.
The Data Bus, information that is carried to and from the processor and main memory.
When we use a real number, we do not store decimal points. As an alternative, we using floating point representation, this is when the decimal point is moved as far left as possible to leave us with a whole number, the mantissa. The number of spaces the decimal place has been moved is known as the exponent.
10011011 x2 0110 > (this would be above)