UNIT- 2
Basic Introduction to Programming Languages
- Differences between Machine-Level language and Assembly language
The following are the differences between machine-level language and assembly language:
Machine-level language | Assembly language |
The machine-level language comes at the lowest level in the hierarchy, so it has zero abstraction level from the hardware. | The assembly language comes above the machine language means that it has less abstraction level from the hardware. |
It cannot be easily understood by humans. | It is easy to read, write, and maintain. |
The machine-level language is written in binary digits, i.e., 0 and 1. | The assembly language is written in simple English language, so it is easily understandable by the users. |
It does not require any translator as the machine code is directly executed by the computer. | In assembly language, the assembler is used to convert the assembly code into machine code. |
It is a first-generation programming language. | It is a second-generation programming language. |
2. Differences between Low-Level language and High-Level language
The following are the differences between low-level language and high-level language:
Low-level language | High-level language |
It is a machine-friendly language, i.e., the computer understands the machine language, which is represented in 0 or 1. | It is a user-friendly language as this language is written in simple English words, which can be easily understood by humans. |
The low-level language takes more time to execute. | It executes at a faster pace. |
It requires the assembler to convert the assembly code into machine code. | It requires the compiler to convert the high-level language instructions into machine code. |
The machine code cannot run on all machines, so it is not a portable language. | The high-level code can run all the platforms, so it is a portable language. |
It is memory efficient. | It is less memory efficient. |
Debugging and maintenance are not easier in a low-level language. | Debugging and maintenance are easier in a high-level language. |
3. Define Machine-level language
The machine-level language is a language that consists of a set of instructions that are in the binary form 0 or 1. As we know that computers can understand only machine instructions, which are in binary digits, i.e., 0 and 1, so the instructions given to the computer can be only in binary codes. Creating a program in a machine-level language is a very difficult task as it is not easy for the programmers to write the program in machine instructions. It is error-prone as it is not easy to understand, and its maintenance is also very high. A machine-level language is not portable as each computer has its machine instructions, so if we write a program in one computer will no longer be valid in another computer.
The different processor architectures use different machine codes, for example, a PowerPC processor contains RISC architecture, which requires different code than Intel x86 processor, which has a CISC architecture.
4. Define Assembly Language
The assembly language contains some human-readable commands such as mov, add, sub, etc. The problems which we were facing in machine-level language are reduced to some extent by using an extended form of machine-level language known as assembly language. Since assembly language instructions are written in English words like mov, add, sub, so it is easier to write and understand.
As we know that computers can only understand the machine-level instructions, so we require a translator that converts the assembly code into machine code. The translator used for translating the code is known as an assembler.
The assembly language code is not portable because the data is stored in computer registers, and the computer has to know the different sets of registers.
The assembly code is not faster than machine code because the assembly language comes above the machine language in the hierarchy, so it means that assembly language has some abstraction from the hardware while machine language has zero abstraction.
5. Define High-Level Language and what are its advantages?
The high-level language is a programming language that allows a programmer to write the programs which are independent of a particular type of computer. The high-level languages are considered as high-level because they are closer to human languages than machine-level languages.
When writing a program in a high-level language, then the whole attention needs to be paid to the logic of the problem.
A compiler is required to translate a high-level language into a low-level language.
Advantages of a high-level language
- The high-level language is easy to read, write, and maintain as it is written in English like words.
- The high-level languages are designed to overcome the limitation of low-level language, i.e., portability. The high-level language is portable; i.e., these languages are machine-independent.
6. What are the types of high level language based on application?
The high-level programming languages can be categorized into different types on the basis of the application area in which they are employed as well as the different design paradigms supported by them. The high-level programming languages are designed for use in a number of areas. Each high-level language is designed by keeping its target application area in mind. Some of the high-level languages are best suited for business domains, while others are apt in the scientific domain only. The high-level language can be categorized on the basis of the various programming paradigms approved by them. The programming paradigms refer to the approach employed by the programming language for solving the different types of problem.
1. Categorisation based on Application
On the basis of application area the high level language can be divided into the following types:
i) Commercial languages
These programming languages are dedicated to the commercial domain and are specially designed for solving business-related problems. These languages can be used in organization for processing handling the data related to payroll, accounts payable and tax building applications. COBOL is the best example of the commercial based high-level programming language employed in the business domain.
Ii) Scientific languages
These programming languages are dedicated to the scientific domain and are specially designed for solving different scientific and mathematical problems. These languages can be used to develop programs for performing complex calculation during scientific research. FORTRAN is the best example of scientific based language.
Iii) Special purpose languages
These programming languages are specially designed for performing some dedicated functions. For example, SQL is a high-level language specially designed to interact with the database programs only. Therefore we can say that the special purpose high-level language is designed to support a particular domain area only.
Iv) General purpose languages
These programming languages are used for developing different types of software application regardless of their application area. The various examples of general purpose high-level programming languages are BASIC, C, C++, and java.
7. What are the types of high level language based on design paradigm?
Categorisation based on Design paradigm
On the basis of design paradigms the high level programming languages can be categorised into the following types:
i) Procedure-oriented languages
These programming languages are also called an imperative programming language. In this language, a program is written as a sequence of procedures. Each procedure contains a series of instruction for performing a specific task. Each procedure can be called by the other procedures during the program execution. In this type of programming paradigms, a code once written in the form of a procedure can be used any number of times in the program by only specifying the corresponding procedure name. Therefore the procedure-oriented language allows the data to move freely around the system. The various examples of procedure-oriented language are FORTRAN, ALGOL, C, BASIC, and ADA.
Ii) Logic-oriented languages
These languages use logic programming paradigms as the design approach for solving various computational problems. In this programming paradigms predicate logic is used to describe the nature of a problem by defining the relationship between rules and facts. Prolog is the best example of the logic-oriented programming language.
Iii) Object-oriented languages
These languages use object-oriented programming paradigms as the design approach for solving a given problem. In this programming language, a problem is divided into a number of objects which can interact by passing messages to each other. C++ and C# are the examples of object-oriented programming language.
8. What are the Relationship between Compiler, Loader and Linker?
Definition
A linker is a computer utility program that takes one or more object files generated by a compiler and combine them into a single executable file. A loader is a part of an operating system that is responsible for loading programs to memory. A compiler is software that transforms computer code written in one programming language (source code) into another programming language (target code). Thus, this explains the main difference between linker loader and compiler.
Functionality
Furthermore, a linker combines multiple object code and links them with libraries. Meanwhile, a loader prepares the executable file for running while a compiler transforms the source code into object code. Therefore, this is the difference between linker loader and compiler in terms of functionality.
Conclusion
In brief, the difference between linker loader and compiler is that a linker combines one or more object files generated by the compiler to a single executable file and a loader places the programs into memory and prepares them for execution while a compiler converts the source code into object code.
9. What is a Flowchart and what are its symbols?
A flowchart is a graphical representations of steps. It was originated from computer science as a tool for representing algorithms and programming logic but had extended to use in all other kinds of processes. Nowadays, flowcharts play an extremely important role in displaying information and assisting reasoning. They help us visualize complex processes, or make explicit the structure of problems and tasks. A flowchart can also be used to define a process or project to be implemented.
Flowchart Symbols
Different flowchart shapes have different conventional meanings. The meanings of some of the more common shapes are as follows:
Terminator
The terminator symbol represents the starting or ending point of the system.
Process
A box indicates some particular operation.
Document
This represents a printout, such as a document or a report.
Decision
A diamond represents a decision or branching point. Lines coming out from the diamond indicates different possible situations, leading to different sub-processes.
Data
It represents information entering or leaving the system. An input might be an order from a customer. Output can be a product to be delivered.
On-Page Reference
This symbol would contain a letter inside. It indicates that the flow continues on a matching symbol containing the same letter somewhere else on the same page.
Off-Page Reference
This symbol would contain a letter inside. It indicates that the flow continues on a matching symbol containing the same letter somewhere else on a different page.
Delay or Bottleneck
Identifies a delay or a bottleneck.
Flow
Lines represent the flow of the sequence and direction of a process.
10. Give some examples of flowchart
Flowchart Example – Simple Algorithms
A flowchart can also be used in visualizing algorithms, regardless of its complexity. Here is an example that shows how flowchart can be used in showing a simple summation process.
Flowchart Example – Calculate Profit and Loss
The flowchart example below shows how profit and loss can be calculated.
