在C ++和C中将'const int'与'int const'作为函数参数 [英] 'const int' vs. 'int const' as function parameters in C++ and C

问题描述

考虑：

  int testfunc1（const int a）
 {
 return a; 
} 
 
 int testfunc2（int const a）
 {
 return a; 
} 
  

这两个功能在各个方面是否都相同还是有区别？ / p>

我对C语言的答案很感兴趣，但是如果C ++语言中有一些有趣的东西，我也想知道。

解决方案

const T 和 T const 相同。使用指针类型会变得更加复杂：

1. const char * 是指向常量 char


2. char const * 是指向常量 char


3. char * const 是指向（可变） char

换句话说，（1）和（2）是相同的。使指针（而不是指针） const 的唯一方法是使用后缀- const 。

这就是为什么许多人总是将 const 放在类型右侧的原因（ East const样式） ：它使它相对于类型的位置一致且易于记忆（从轶事上看，它也使得对初学者的学习更容易）。

Consider:

int testfunc1 (const int a)
{
  return a;
}

int testfunc2 (int const a)
{
  return a;
}

Are these two functions the same in every aspect or is there a difference?

I'm interested in an answer for the C language, but if there is something interesting in the C++ language, I'd like to know as well.

解决方案

const T and T const are identical. With pointer types it becomes more complicated:

1. const char* is a pointer to a constant char
2. char const* is a pointer to a constant char
3. char* const is a constant pointer to a (mutable) char

In other words, (1) and (2) are identical. The only way of making the pointer (rather than the pointee) const is to use a suffix-const.

This is why many people prefer to always put const to the right side of the type ("East const" style): it makes its location relative to the type consistent and easy to remember (it also anecdotally seems to make it easier to teach to beginners).

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