Programming Languages: Low-Level

• A programming language (PL) is a vocabulary and set of grammatical rules for instructing a computer to perform specific tasks.
• A programming language is a set of commands, instructions, and other syntax used to create a software program.
• There are about 700 programming languages.
• A computer program is a list of instructions that enable a computer to perform a specific task.
• Programming languages are classified into two main categories: low-level and high-level.

Low-Level Languages

• Used to write programs that relate to the specific architecture and hardware of a particular computer.
• Closer to the native language of a computer (binary), making them harder to understand.
• Often relates to the specific architecture and hardware of a particular type of computer
• One line of low level code becomes one line of machine code
• Examples include Machine Code and Assembly Language.

Advantages

• Can use special hardware or machine-dependent instructions.
• Translated program requires less memory.
• Write code that can be executed faster.
• Total control over the code.
• Can work directly on memory locations.

Disadvantages

• Programs are machine dependent and not portable.
• Error detection and maintenance are tedious and time-consuming.
• More error-prone.
• Programming usually results in poor programming productivity.
• Programmers must have additional knowledge of the computer architecture.

High-Level Languages

• Written in a form that is close to human language.
• Enables a programmer to focus on the problem being solved.
• No particular knowledge of the hardware is needed.
• Programs are portable and not tied to a specific computer.
• Statements are easier to understand than low-level languages.
• No knowledge of computer hardware is needed.
• One line of high level code becomes many lines of machine code
• Examples include C++, Java, Pascal, Python, and Visual Basic.

Advantages

• Easier to modify as it uses English-like statements.
• Easier and faster to write code.
• Easier to debug during development due to English-like statements.
• Code is portable.

Disadvantages

Generations of Programming Languages

• Programming languages have been developed in phases, each more user-friendly and powerful.
• Each phase of improvement is referred to as a generation. The programming language in terms of their performance reliability and robustness can be grouped into five different generations
• The trend has been moving towards more abstraction, ease of use, and flexibility in expressing complex logic and operations.

First Generation (1GL) - Machine Language:

• Consists of binary codes (0s and 1s).
• Directly executed by a computer without any translation.
• Highly hardware-specific.

Second Generation (2GL) - Assembly Language:

• Uses mnemonic codes and symbolic addresses instead of binary.
• Requires an assembler to convert to machine code.
• Provides more abstraction than machine language but is still closely tied to the machine architecture.

Third Generation (3GL) - High-Level Programming Languages:

• Abstracts machine details and allows developers to write more human-readable code.
• Includes languages like C, C++, Fortran, COBOL, Java, and Pascal.
• Requires compilers or interpreters to translate to machine code or bytecode.
• Introduces structured programming paradigms.

Fourth Generation (4GL) - Very High-Level Programming Languages:

• Further abstracts programming concepts and is often task-specific.
• Often used for database interaction, report generation, and some business applications.
• Examples include SQL, MATLAB, and tools like Oracle Reports.

Fifth Generation (5GL) - Constraint-based or Logic Programming Languages:

• Focused on solving problems using constraints given instead of a specific algorithm.
• Prolog is an example.
• Used primarily for artificial intelligence and knowledge-based applications.