Computer Science GCES AQA
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Representing Algorithms Aqa4 主题
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Efficiency Of Algorithms Aqa1 主题
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Searching Algorithms Aqa3 主题
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Sorting Algorithms Aqa3 主题
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Data Types Aqa1 主题
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Programming Concepts Aqa5 主题
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Arithmetic Relational And Boolean Operations Aqa1 主题
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Data Structures Aqa3 主题
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String Manipulation Aqa1 主题
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Random Number Generation Aqa1 主题
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Structured Programming Aqa2 主题
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Robust And Secure Programming Aqa4 主题
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Number Bases Aqa2 主题
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Converting Between Number Bases Aqa3 主题
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Units Of Information Aqa9 主题
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Hardware And Software Aqa4 主题
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Boolean Logic Aqa3 主题
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Programming Languages And Translators Aqa2 主题
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Cpu Architecture Performance And Embedded Systems Aqa4 主题
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Memory Aqa2 主题
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Secondary Storage Aqa3 主题
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Fundamentals Of Computer Networks Aqa8 主题
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Fundamentals Of Cyber Security Aqa1 主题
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Methods Of Preventing Cyber Security Threats Aqa1 主题
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Relational Databases Aqa2 主题
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Ethical Legal And Environmental Impacts Aqa2 主题
Levels Of Programming Langauges Aqa
Exam code:8525
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Since the invention of the computer, people have needed to learn how to communicate with them using programming languages
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Early computers were complex and instructions would have to be in written in binary code, 0s and 1s
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This process was slow, taking days to program simple tasks
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Over time, new generations of programming languages have enabled people to become faster and more efficient at writing programs as they resemble human language
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Generations of programming languages can be split in to two categories:
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Low-level
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First generation
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Second generation
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High-level
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Third generation
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Low-Level Languages
What is a low-level language?
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A low-level language is a programming language that directly translates to machine code understood by the processor
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Low-level languages allow direct control over hardware components such as memory and registers
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These languages are written for specific processors to ensure they embed the correct machine architecture
First generation
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Machine code is a first-generation language
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Instructions are directly executable by the processor
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Written in binary code
Second generation
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Assembly code is a second-generation language
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The code is written using mnemonics, abbreviated text commands such as LDA (Load), STA(Store)
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Using this language programmers can write human-readable programs that correspond almost exactly to machine code
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One assembly language instruction translates to one machine code instruction
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Needs to be translated into machine code for the computer to be able to execute it
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Advantages |
Disadvantages |
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Complete control over the system components |
Difficult to write and understand |
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Occupy less memory and execute faster |
Machine dependent |
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Direct manipulation of hardware |
More prone to errors |
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Knowledge of computer architecture is key to program effectively |
High-Level Languages
What is a high-level programming language?
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A high-level programming language uses English-like statements to allow users to program with easy to use code
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Most computer programs are now written in high-level languages
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High-level languages allow for clear debugging and once programs are created they are easier to maintain
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High level languages were needed due to the development of processor speeds and the increase in memory capacity
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One instruction translates into many machine code instructions
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Needs to be translated into machine code for the computer to be able to execute it
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Examples of high-level languages include:
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Python
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Java
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Basic
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C+
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Advantages |
Disadvantages |
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Easier to read and write |
The user is not able to directly manipulate the hardware |
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Easier to debug |
Needs to be translated to machine code before running |
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Portable so can be used on any computer |
The program may be less efficient |
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One line of code can perform multiple commands |
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