Levels of Programming Languages
What is a programming language?
A programming language acts as a bridge between what humans understand and what a computer understands
Early computers were complex and instructions would have to be in written in binary code, 0s and 1s
This process was slow, taking days to program simple tasks
Over time, new generations of programming languages have enabled people to become faster and more efficient at writing programs as they resemble human language
Generations of programming languages can be split in to two categories:
Low-level
First generation
Second generation
High-level
Third generation
Low-Level Languages
Low-Level Languages
What is a low-level language?
A low-level language is a programming language that directly translates to machine code understood by the processor
Low-level languages allow direct control over hardware components such as memory and registers
These languages are written for specific processors to ensure they embed the correct machine architecture
First generation
Machine code is a first-generation language
Instructions are directly executable by the processor
Written in binary code
Second generation
Assembly code is a second-generation language
The code is written using mnemonics, abbreviated text commands such as LDA (Load), STA(Store)
Using this language programmers can write human-readable programs that correspond almost exactly to machine code
One assembly language instruction translates to one machine code instruction
Needs to be translated into machine code for the computer to be able to execute it
Advantages | Disadvantages |
|---|---|
Complete control over the system components | Difficult to write and understand |
Occupy less memory and execute faster | Machine dependent |
Direct manipulation of hardware | More prone to errors |
| Knowledge of computer architecture is key to program effectively |
High-Level Languages
High-Level Languages
What is a high-level language?
A high-level programming language uses English-like statements to allow users to program with easy to use code
High-level languages allow for clear debugging and once programs are created they are easier to maintain
High level languages were needed due to the development of processor speeds and the increase in memory capacity
One instruction translates into many machine code instructions
Needs to be translated into machine code for the computer to be able to execute it
Examples of high-level languages include:
Python
Java
Basic
C++
Advantages | Disadvantages |
|---|---|
Easier to read and write | The user is not able to directly manipulate the hardware |
Easier to debug | Needs to be translated to machine code before running |
Portable so can be used on any computer | The program may be less efficient |
One line of code can perform multiple commands |
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