Code performance

What will also impact the performance of an application is a choice of a programming language. Again I will not recommend one or another. It depends on the skill set of people that develop on it.

Some programming languages compile into machine code. They are called compiled languages. Example of a compiled language is C/C++. Programs written in these are usually fast. But it is difficult to debug an issue in these if a problem occurs because compiled files are not human readable. Compiled code targets a specific processor architecture only. Many of the modern processors have backward compatibility. They will execute code that was written for the older generation of processors.

Opposite of a compiled programming language is an interpreted programming language. Every time it runs it needs a special software that translates human readable code into machine’s code. Advantage of these programming languages: they are easier to troubleshoot than compiled languages. Disadvantage of these, they are usually slower. Examples of these are Perl and PHP.

Is there anything in the middle? Yes it is. Program code is compiled into an intermediate code, which requires a special software to interpret what needs to be done. Example of this programming language is C# (it reads as C Sharp). Programs that are written in these languages are usually as fast as the code written in a compiled language. If these programs are as fast, what then a drawback is? These programs are usually much bigger in size than programs written in a compiled language.

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Study Guide: Compiled vs. Interpreted Programming Languages

Key Concepts to Understand

Compiled Languages: Understand the process of compilation into machine code, the resulting performance characteristics (speed), debugging challenges, and platform dependency. Recognize examples like C/C++.

Interpreted Languages: Understand how interpreted languages execute code line by line using an interpreter, the resulting performance characteristics (speed), ease of debugging, and platform independence. Recognize examples like Perl and PHP.

Intermediate Code Languages: Understand the hybrid approach where code is compiled to an intermediate representation (bytecode) and then interpreted by a virtual machine. Understand the performance characteristics (speed), debugging considerations, platform independence, and potential drawbacks like larger file sizes. Recognize examples like C#.

Machine Code: Define what machine code is and why it is directly executable by a computer's processor.

Human Readable Code: Understand what human-readable code is (source code) and why it needs to be translated for a computer to execute it.

Debugging: Understand the process of identifying and fixing errors in computer programs and how the nature of compiled and interpreted languages affects this process.

Processor Architecture: Understand that different types of computer processors have different sets of instructions they can execute.

Backward Compatibility: Understand how newer processors can often execute code designed for older processor generations.

Interpreter: Define the role of an interpreter in executing interpreted languages.

Compiler: Define the role of a compiler in translating source code into machine code.

Intermediate Code (Bytecode): Define what intermediate code is and the role of a virtual machine in executing it.

Quiz

Describe the primary difference in how compiled and interpreted languages execute program code.

What is a key advantage of using a compiled programming language in terms of performance? Explain why this advantage exists.

Why can debugging be more challenging in compiled languages compared to interpreted languages?

Explain the concept of platform dependency in the context of compiled programming languages.

How do interpreted programming languages handle the translation of code into machine instructions? What is a resulting benefit in terms of debugging?

What is a main performance disadvantage often associated with interpreted programming languages? Explain the reason for this.

Describe the "middle ground" approach to programming language execution. What are the two stages involved?

According to the source, what is a potential performance advantage of languages that use intermediate code compared to purely interpreted languages?

What is a noted drawback, other than potential complexity, of programming languages that compile to intermediate code?

Explain the role of backward compatibility in the context of compiled code and processor architecture.

Quiz Answer Key

Compiled languages translate the entire source code into machine code before execution, resulting in a standalone executable. Interpreted languages, on the other hand, translate and execute code line by line every time the program runs.

A key advantage of compiled languages is their speed. This is because the translation to machine code happens only once, and the resulting executable runs directly on the processor without the need for real-time translation.

Debugging can be more difficult in compiled languages because the compiled files (machine code) are not human-readable. When an error occurs at runtime, the error message might refer to a location in the compiled code, making it harder to trace back to the original source code.

Platform dependency in compiled languages means that the machine code generated by the compiler is typically specific to a particular processor architecture and operating system. Therefore, a compiled program for one platform may not run on another without recompilation.

Interpreted programming languages use a special software called an interpreter to read the human-readable code and translate it into the machine's code instruction by instruction as the program is running. This allows for easier troubleshooting because errors can often be traced back to the specific line of source code being interpreted.

A main performance disadvantage of interpreted languages is that they are usually slower than compiled languages. This is because each line of code needs to be translated into machine code every time the program runs, adding overhead.

The "middle ground" approach involves compiling the program code into an intermediate code (like bytecode). This intermediate code is then executed by a special software, often a virtual machine, which interprets the intermediate code into machine instructions.

Programs written in languages that compile to intermediate code are often as fast as code written in compiled languages. This is because the initial compilation step optimizes the code into a more efficient intermediate representation before interpretation.

A noted drawback of programming languages that compile to intermediate code is that the resulting program files are usually much bigger in size than programs written in a compiled language.

Backward compatibility refers to the ability of newer generations of processors to execute code that was originally written for older processor generations. This allows users to run older compiled software on newer hardware.

Essay Format Questions

Compare and contrast the execution models of compiled and interpreted programming languages, discussing their respective advantages and disadvantages in terms of performance and debugging.

Explain the concept of platform dependency and discuss how it relates differently to compiled and interpreted programming languages. Consider the role of intermediate code in mitigating platform dependency.

Analyze the "middle ground" approach of compiling to intermediate code. What are the potential benefits and drawbacks of this hybrid model compared to purely compiled or purely interpreted languages?

Discuss the trade-offs a software developer might consider when choosing between a compiled language (like C++) and an interpreted language (like PHP) for a specific project.

Considering the evolution of computing, evaluate the continued relevance and specific use cases for compiled, interpreted, and intermediate code-based programming languages.

Glossary of Key Terms

Compiled Language: A programming language where the source code is translated entirely into machine code by a compiler before execution.

Interpreted Language: A programming language where the source code is executed line by line by an interpreter, without prior compilation into machine code.

Intermediate Code (Bytecode): A platform-independent representation of source code that is produced by a compiler and then executed by a virtual machine or interpreter.

Machine Code: The lowest-level programming language consisting of binary instructions that a computer's central processing unit (CPU) can directly execute.

Human Readable Code (Source Code): The code written by programmers in a high-level programming language, which is understandable by humans.

Debugging: The process of identifying and fixing errors (bugs) in computer programs.

Processor Architecture: The design and organization of a computer's central processing unit (CPU), including the set of instructions it can execute.

Backward Compatibility: The ability of newer hardware or software to work with older hardware or software.

Interpreter: A program that reads and executes source code line by line, translating each line into machine code as it is being run.

Compiler: A program that translates the entire source code of a program into machine code or an intermediate code before the program is executed.

Virtual Machine: A software environment that emulates a physical computer, allowing code compiled to an intermediate format (like bytecode) to run on different platforms.

Frequently Asked Questions about Compiled and Interpreted Programming Languages

Q1. What is a compiled programming language, and what are its key characteristics?

A compiled programming language translates the entire source code into machine code (instructions directly executable by the computer's processor) before the program is run. Key characteristics include faster execution speeds once compiled because the translation step is already completed. However, debugging can be more challenging as you are working with machine code, which is not human-readable. Additionally, the resulting executable is typically specific to a particular processor architecture, although backward compatibility within processor families often exists. Examples include C and C++.

Q2. How does an interpreted programming language differ from a compiled one?

In contrast to compiled languages, an interpreted programming language executes code line by line. Each time the program runs, a special program called an interpreter translates the human-readable source code into machine code on the fly. This makes debugging generally easier because you are working directly with the source code. However, interpreted languages tend to be slower than compiled languages because of the overhead of interpreting the code during each execution. Examples include Perl and PHP.

Q3. What are the trade-offs between using a compiled language versus an interpreted language?

The primary trade-offs revolve around execution speed, ease of debugging, and portability. Compiled languages offer faster runtime performance but can be harder to debug and might require recompilation for different processor architectures. Interpreted languages are typically slower but provide easier debugging and often greater platform independence because the interpreter handles the underlying system differences.

Q4. What is an intermediate approach that combines aspects of both compiled and interpreted languages?

Some programming languages employ a hybrid approach where the source code is first compiled into an intermediate code (often called bytecode). This intermediate code is not machine code for a specific processor but rather a platform-independent representation. Then, a virtual machine or interpreter executes this intermediate code.

Q5. What is an example of a programming language that uses an intermediate code approach?

C# (pronounced C Sharp) is a prominent example of a language that compiles to an intermediate code. The C# compiler produces Common Intermediate Language (CIL), which is then executed by the .NET Common Language Runtime (CLR), a virtual machine.

Q6. What are the advantages of using an intermediate code approach?

Languages using intermediate code often achieve a balance between the performance of compiled languages and the flexibility of interpreted languages. The initial compilation to intermediate code allows for some performance optimizations. Furthermore, the platform independence of the intermediate code enables "write once, run anywhere" capabilities, provided the appropriate virtual machine or interpreter is available for the target platform.

Q7. If languages using intermediate code can be as fast as compiled languages, what are their potential drawbacks?

While performance can be comparable, a potential drawback of languages using intermediate code is the size of the resulting program. The compiled intermediate code, along with the necessary virtual machine or runtime environment, can often result in a larger overall footprint compared to a directly compiled executable.

Q8. How does processor architecture compatibility relate to compiled code?

Compiled code is typically targeted at a specific processor architecture (e.g., x86, ARM). While modern processors often have backward compatibility, allowing them to run code compiled for older generations of the same architecture, an executable compiled for one architecture generally cannot run directly on a different architecture without recompilation. This contrasts with interpreted languages, where the interpreter handles the underlying architecture differences, and intermediate code languages, where the virtual machine provides a level of abstraction.