我想更好地理解其中的区别。我在网上找到了很多解释,但它们都倾向于抽象的差异,而不是实际的含义。

Most of my programming experiences has been with CPython (dynamic, interpreted), and Java (static, compiled). However, I understand that there are other kinds of interpreted and compiled languages. Aside from the fact that executable files can be distributed from programs written in compiled languages, are there any advantages/disadvantages to each type? Oftentimes, I hear people arguing that interpreted languages can be used interactively, but I believe that compiled languages can have interactive implementations as well, correct?


当前回答

从http://www.quora.com/What-is-the-difference-between-compiled-and-interpreted-programming-languages

There is no difference, because “compiled programming language” and “interpreted programming language” aren’t meaningful concepts. Any programming language, and I really mean any, can be interpreted or compiled. Thus, interpretation and compilation are implementation techniques, not attributes of languages. Interpretation is a technique whereby another program, the interpreter, performs operations on behalf of the program being interpreted in order to run it. If you can imagine reading a program and doing what it says to do step-by-step, say on a piece of scratch paper, that’s just what an interpreter does as well. A common reason to interpret a program is that interpreters are relatively easy to write. Another reason is that an interpreter can monitor what a program tries to do as it runs, to enforce a policy, say, for security. Compilation is a technique whereby a program written in one language (the “source language”) is translated into a program in another language (the “object language”), which hopefully means the same thing as the original program. While doing the translation, it is common for the compiler to also try to transform the program in ways that will make the object program faster (without changing its meaning!). A common reason to compile a program is that there’s some good way to run programs in the object language quickly and without the overhead of interpreting the source language along the way. You may have guessed, based on the above definitions, that these two implementation techniques are not mutually exclusive, and may even be complementary. Traditionally, the object language of a compiler was machine code or something similar, which refers to any number of programming languages understood by particular computer CPUs. The machine code would then run “on the metal” (though one might see, if one looks closely enough, that the “metal” works a lot like an interpreter). Today, however, it’s very common to use a compiler to generate object code that is meant to be interpreted—for example, this is how Java used to (and sometimes still does) work. There are compilers that translate other languages to JavaScript, which is then often run in a web browser, which might interpret the JavaScript, or compile it a virtual machine or native code. We also have interpreters for machine code, which can be used to emulate one kind of hardware on another. Or, one might use a compiler to generate object code that is then the source code for another compiler, which might even compile code in memory just in time for it to run, which in turn . . . you get the idea. There are many ways to combine these concepts.

其他回答

编译语言是这样一种语言:程序一旦编译,就用目标机器的指令来表达。例如,源代码中的加法“+”操作可以直接转换为机器代码中的“ADD”指令。

解释型语言是指指令不直接由目标机器执行,而是由其他程序(通常用本机语言编写)读取和执行的语言。例如,相同的“+”操作将在运行时被解释器识别,然后调用它自己的“add(a,b)”函数,并使用适当的参数,然后执行机器代码“add”指令。

你可以在编译语言中做你在解释语言中可以做的任何事情,反之亦然——它们都是图灵完备的。然而,这两种方法在实施和使用方面都有优点和缺点。

我将完全概括(纯粹主义者原谅我!),但大致来说,以下是编译语言的优点:

通过直接使用目标计算机的本机代码获得更快的性能 有机会在编译阶段应用相当强大的优化

下面是解释型语言的优点:

更容易实现(编写好的编译器非常困难!!) 不需要运行编译阶段:可以直接“动态”执行代码 是否可以更方便地使用动态语言

注意,字节码编译等现代技术增加了一些额外的复杂性——这里发生的情况是,编译器的目标是一个与底层硬件不同的“虚拟机”。这些虚拟机指令可以在稍后阶段再次编译,以获得本机代码(例如,由Java JVM JIT编译器完成)。

解释源代码相对于编译源代码的最大优势是可移植性。

如果你的源代码是编译的,你需要为你的程序运行在不同类型的处理器和/或平台编译不同的可执行文件(例如一个用于Windows x86,一个用于Windows x64,一个用于Linux x64,等等)。此外,除非您的代码完全符合标准,并且不使用任何特定于平台的函数/库,否则您实际上需要编写和维护多个代码库!

如果你的源代码是解释型的,你只需要编写一次,它就可以在任何平台上由合适的解释器解释和执行!它是便携!请注意,解释器本身是为特定平台编写和编译的可执行程序。

编译代码的一个优点是它向最终用户隐藏了源代码(可能是知识产权),因为您部署的不是人类可读的原始源代码,而是一个模糊的二进制可执行文件。

编译器和解释器做同样的工作:将一种编程语言翻译成另一种编程语言,通常更接近硬件,通常是直接可执行的机器代码。

Traditionally, "compiled" means that this translation happens all in one go, is done by a developer, and the resulting executable is distributed to users. Pure example: C++. Compilation usually takes pretty long and tries to do lots of expensive optmization so that the resulting executable runs faster. End users don't have the tools and knowledge to compile stuff themselves, and the executable often has to run on a variety of hardware, so you can't do many hardware-specific optimizations. During development, the separate compilation step means a longer feedback cycle.

Traditionally, "interpreted" means that the translation happens "on the fly", when the user wants to run the program. Pure example: vanilla PHP. A naive interpreter has to parse and translate every piece of code every time it runs, which makes it very slow. It can't do complex, costly optimizations because they'd take longer than the time saved in execution. But it can fully use the capabilities of the hardware it runs on. The lack of a separrate compilation step reduces feedback time during development.

But nowadays "compiled vs. interpreted" is not a black-or-white issue, there are shades in between. Naive, simple interpreters are pretty much extinct. Many languages use a two-step process where the high-level code is translated to a platform-independant bytecode (which is much faster to interpret). Then you have "just in time compilers" which compile code at most once per program run, sometimes cache results, and even intelligently decide to interpret code that's run rarely, and do powerful optimizations for code that runs a lot. During development, debuggers are capable of switching code inside a running program even for traditionally compiled languages.

从http://www.quora.com/What-is-the-difference-between-compiled-and-interpreted-programming-languages

There is no difference, because “compiled programming language” and “interpreted programming language” aren’t meaningful concepts. Any programming language, and I really mean any, can be interpreted or compiled. Thus, interpretation and compilation are implementation techniques, not attributes of languages. Interpretation is a technique whereby another program, the interpreter, performs operations on behalf of the program being interpreted in order to run it. If you can imagine reading a program and doing what it says to do step-by-step, say on a piece of scratch paper, that’s just what an interpreter does as well. A common reason to interpret a program is that interpreters are relatively easy to write. Another reason is that an interpreter can monitor what a program tries to do as it runs, to enforce a policy, say, for security. Compilation is a technique whereby a program written in one language (the “source language”) is translated into a program in another language (the “object language”), which hopefully means the same thing as the original program. While doing the translation, it is common for the compiler to also try to transform the program in ways that will make the object program faster (without changing its meaning!). A common reason to compile a program is that there’s some good way to run programs in the object language quickly and without the overhead of interpreting the source language along the way. You may have guessed, based on the above definitions, that these two implementation techniques are not mutually exclusive, and may even be complementary. Traditionally, the object language of a compiler was machine code or something similar, which refers to any number of programming languages understood by particular computer CPUs. The machine code would then run “on the metal” (though one might see, if one looks closely enough, that the “metal” works a lot like an interpreter). Today, however, it’s very common to use a compiler to generate object code that is meant to be interpreted—for example, this is how Java used to (and sometimes still does) work. There are compilers that translate other languages to JavaScript, which is then often run in a web browser, which might interpret the JavaScript, or compile it a virtual machine or native code. We also have interpreters for machine code, which can be used to emulate one kind of hardware on another. Or, one might use a compiler to generate object code that is then the source code for another compiler, which might even compile code in memory just in time for it to run, which in turn . . . you get the idea. There are many ways to combine these concepts.

The Python Book©2015 Imagine Publishing Ltd,简单地通过第10页中提到的以下提示来区分差异:

像Python这样的解释型语言是指将源代码转换为机器码,然后在每次程序运行时执行的语言。这与编译语言(如C)不同,后者只将源代码转换为机器代码一次——然后在程序每次运行时执行生成的机器代码。