Compiler and Interpreter: Compiled Language vs Interpreted Programming Languages

Summary

This script explains the two primary methods for executing source code: compiling and interpreting. Compiling involves converting source code into machine code via a compiler, creating an executable file that can be distributed and run without revealing the original code. Interpreting, on the other hand, sends the source code to the user's machine, which is then processed line by line by an interpreter. The script also introduces a hybrid approach, where code is partially compiled into an intermediate language like bytecode and then completed on the user's machine, known as JIT compilation. The choice between these methods depends on factors like platform compatibility, speed, and the need for source code secrecy.

Takeaways

• 🤖 **Compilation vs Interpretation**: There are two main methods to convert source code into machine code - compiling and interpreting.
• 💾 **Compiled Languages**: With compiled languages, a compiler converts source code into a separate executable file containing machine code.
• 🔍 **Executable Files**: Compiled code results in executable files that can be directly run on the target machine without revealing the source code.
• 🌐 **Portability of Compiled Code**: Compiled code may not be portable across different platforms or CPUs without recompilation.
• 📝 **Interpreted Languages**: Interpreted languages do not require pre-compilation; the source code is sent and run on the target machine using an interpreter.
• 🌀 **On-the-fly Interpretation**: Interpreters process the source code line by line, converting it to machine code during runtime.
• 🌐 **Universality of Interpreted Code**: Interpreted code is platform-independent as it sends the source code to be run on any machine with the appropriate interpreter.
• 🔧 **Ease of Debugging**: Interpreted languages are easier to debug because the full source code is available for examination.
• 🏎️ **Speed and Optimization**: Compiled code tends to run faster and can be optimized for specific CPUs, but interpreted code may be slower due to the need for real-time interpretation.
• 🔄 **Hybrid Approach (JIT Compilation)**: Some languages use a hybrid approach, compiling to an intermediate language or bytecode, which is then compiled to machine code on the target machine, offering a balance between speed and portability.

Q & A

What are the two main ways of converting source code into machine code?

The two main ways of converting source code into machine code are compiling and interpreting.

What is a compiler and what does it do?

A compiler is a program that takes source code and converts it into machine code, creating a separate executable file that can be directly run on a computer.

What is the benefit of using a compiled language?

Compiled languages offer the benefit of creating an executable file that is ready to run, can be optimized for a CPU, and does not require the source code to be sent to every user.

What are the downsides of using a compiled language?

Downsides of compiled languages include the need for separate compilation for different CPUs, the extra step of compiling before testing, and the lack of portability across different platforms.

How does an interpreter work with source code?

An interpreter processes source code line by line on the fly, without saving it as a separate machine code file, allowing the code to be run directly from the source.

What is the advantage of using an interpreted language?

Interpreted languages are portable and flexible across platforms, easier to test since there's no compile step, and debugging is often simpler because the source code is always accessible.

What are the potential drawbacks of using an interpreted language?

Drawbacks of interpreted languages include the need for an interpreter on every machine that runs the program, potential slower performance due to the interpretation process, and the source code being effectively public.

What is the hybrid approach between compiling and interpreting?

The hybrid approach involves compiling the source code to an intermediate language, such as bytecode, which is then completed to machine code by the user's machine, often using just-in-time (JIT) compilation.

Why might a language use an intermediate language like bytecode?

Using an intermediate language like bytecode allows for a balance between the upfront work of compiling and the flexibility of interpreting, often resulting in better portability across platforms.

Which programming languages are typically compiled, and why?

Languages like C, C++, and Objective-C are typically compiled because they often require optimization for specific CPUs and are used for performance-critical applications.

How does the choice of programming language relate to whether the code is compiled, interpreted, or uses a hybrid approach?

The choice of programming language is often driven by the needs of the project, such as the target platform or the required performance, which in turn determines whether the language is compiled, interpreted, or uses a hybrid approach.