The fastest running code would be carefully hand crafted machine code. Assembler will be almost as good. Both are very low level and it takes a lot of writing code to do things. C is a little above assembler. You still have the ability to control things at a very low level in the actual machine, but there is enough abstraction make writing it faster and easier then assembler. Other languages such as C# and JAVA are even more abstract. While Assembler and machine code are called low level languages, C# and JAVA (and many others) are called high level languages. C is sometimes called a middle level language.

The lack of abstraction is what makes C faster. If you write an output statement you know exactly what is happening. If you write an output statement in java it is getting compiled to a class file which then gets run on a virtual machine introducing a layor of abstraction. The lack of object oriented features as a part of the language also increases it's speed do to less code being generated. If you use C as an object oriented language then you are doing all the coding for things such as classes, inharitence, etc. This means rather then make something generalized enough for everyone with the amount of code and the performance penelty that requires you only write what you need to get the job done.

我还没有看到它，所以我要说:C往往更快，因为几乎所有其他东西都是用C写的。

Java是建立在C上的，Python是建立在C上的(或者Java，或者。net等等)，Perl是等等。操作系统是用C写的，虚拟机是用C写的，编译器是用C写的，解释器是用C写的，有些东西仍然是用汇编语言写的，这往往更快。越来越多的东西是用别的东西写的，而这些东西本身就是用C写的。

您用其他语言(不是Assembly)编写的每个语句通常都在下面实现为C中的几个语句，这些语句被编译为本机机器代码。由于其他语言的存在往往是为了获得比C更高的抽象级别，因此C中所需的那些额外语句往往侧重于增加安全性、增加复杂性和提供错误处理。这些通常都是好事，但它们是有代价的，那就是速度和规模。

就我个人而言，我已经用几十种语言写过了，涵盖了大部分可用的范围，我个人也一直在寻找你暗示的魔法:

我怎样才能鱼与熊掌兼得呢?我如何在我最喜欢的语言中玩高级抽象，然后为了速度而降至C语言的细节?

经过几年的研究，我的答案是Python(在C上)。你可能想看看它。顺便说一下，您也可以从Python下拉到Assembly(从一个特殊的库中获得一些小小的帮助)。

另一方面，任何语言都可能编写出糟糕的代码。因此，C(或汇编)代码不会自动更快。同样，一些优化技巧可以使部分高级语言代码的性能水平接近原始c语言的性能水平。但是，对于大多数应用程序来说，程序的大部分时间都在等待人员或硬件，因此两者之间的差异实际上并不重要。

享受。

C语言速度很快，因为它是原生编译的低级语言。但是C不是最快的。递归斐波那契基准测试表明Rust、Crystal和Nim可以更快。

这不是语言的问题，而是工具和库的问题。C语言可用的库和编译器比新语言要老得多。你可能认为这会让它们变慢，但事实恰恰相反。

这些库是在处理能力和内存非常重要的时候编写的。它们必须写得非常高效，才能发挥作用。C编译器的开发人员也花了很长时间为不同的处理器进行各种巧妙的优化。C语言的成熟和广泛采用使得它比同时期的其他语言具有显著的优势。它还使C语言在速度上比那些不像C语言那样强调原始性能的新工具更有优势。

For the most part, every C instruction corresponds to a very few assembler instructions. You are essentially writing higher level machine code, so you have control over almost everything the processor does. Many other compiled languages, such as C++, have a lot of simple looking instructions that can turn into much more code than you think it does (virtual functions, copy constructors, etc..) And interpreted languages like Java or Ruby have another layer of instructions that you never see - the Virtual Machine or Interpreter.