Programming Languages. (II)

Programming Languages

Lesson 2

High and Low Level Languages

• A computer program is a list of instructions that enable a computer to perform a specific task.

• Computer programs can be written in high and low level languages, depending on the task and the hardware being used.

• So, what’s the difference between high level language and low level language?

High Level Languages

• When we think about computer programmers, we are probably thinking about people who write in high-level programming languages.

• High level languages are written in a form that is close to our human language, enabling to programmer to just focus on the problem being solved.

• No particular knowledge of the hardware is needed as high level languages create programs that are portable and not tied to a particular computer or microchip.

• These programmer friendly languages are called ‘high level’ as they are far removed from the machine code instructions understood by the computer.

• Examples include: C++, Java, Pascal, Python, Visual Basic.

Advantages of high-level languages

• Easier to modify as it uses English like statements

• Easier/faster to write code as it uses English like statements

• Easier to debug during development due to English like statements

• Portable code – not designed to run on just one type of machine

Low Level Languages

• Low level languages are used to write programs that relate to the specific architecture and hardware of a particular type of computer.

• They are closer to the native language of a computer (binary), making them harder for programmers to understand.

Examples of low level language:

• Assembly language

• Machine code

Assembly Language

• Few programmers write programs in low level assembly language, but it is still used for developing code for specialist hardware, such as device drivers.

• It is easyly distinguishable from a high level language as it contains few recognisable human words but plenty of mnemonic code.

Advantages of assembly language

• Can make use of special hardware or special machine-dependent instructions (e.g. on the specific chip)

• Translated program requires less memory

• Write code that can be executed faster

• Total control over the code

• Can work directly on memory locations

Machine Code

• Programmers rarely write in machine code (binary) as it is difficult to understand.

Multiple Choice

Which generation?

• Machine Code - Low

• Assembly Code - Low

• High Level

Multiple Choice

Which generation?

• Machine Code - Low

• Assembly Code - Low

• High Level

Multiple Choice

Which generation?

• Machine Code - Low

• Assembly Code - Low

• High Level

Multiple Choice

A disadvantage of programming in Low Level is

• No technical skill is required
• Needs to be translated before it can be executed
• Difficult for humans to debug

Multiple Choice

An advantage of programming in Low Level is

• Easier for us to understand
• Easier to debug
• Programs require less file space

Multiple Choice

Python is an example of a High Level programming language

• True

• False

Multiple Choice

Which level would create the easiest code for humans to understand?

• Low

• Assembly

• High

Multiple Choice

Which level of a programming language is Assembly Code?

• Low

• High

Multiple Choice

Which level of a programming language is Machine Code?

• Low

• High