c++ - 在 C++ 中向 char* 添加 char 前缀的最佳方法？

Question

我需要为 char* 添加一个前缀（'X'）（“很酷”）。

做这个的最好方式是什么？

最简单的方法是什么？

char a = 'X';
char* b= " is cool";

我需要：

char* c = "X is cool";

到目前为止，我尝试了 strcpy-strcat、memcpy；

我知道这听起来是一个愚蠢的、未经研究的问题。我想知道是否有一种方法可以将 char 添加到数组而不将 char 转换为字符串。

Answer 1

使用 C++ 标准库而不是 C 库函数怎么样？

auto a = 'X';
auto b = std::string{" is cool"};
b = a+b;

或简称：

auto a ='X';
auto b = a+std::string{" is cool"};

请注意，强制转换为字符串。

Answer 2

也许您可以使用字符串而不是 char* ？

std::string p = " is cool";
std::string x = 'X' + p;

Answer 3

您正在使用 C++，因此为此目的，不要char*用于字符串，请使用std::string.

std::string str = std::string("X") + std::string(" is cool");
// Or:
std::string str = std::string("X") + " is cool";
// Or:
std::string str = 'X' + std::string(" is cool");
// Or:
std::string str = std::string{" is cool"};

这就像一个魅力，它表达了你的意图，它可读且易于输入。（主观的，是的，但无论如何。）

---

In case you really need to use char* though, do note that char* b = " is cool"; is invalid because you're using a string literal. Consider using char b[] = " is cool";. That is an array of chars.

You would use strcat assuring that enough memory is allocated for the destination string.

char a[32] = "X"; // The size must change based on your needs.
                  // See, this is why people use std::string ;_;
char b[] = " is cool";

// This will concatenate b to a
strcat(a, b);

// a will now be "X is cool"

But seriously man, avoid the C-side of C++ and you will be happier and more productive [citation needed].

Answer 4

尝试，

char a[20] = "X";
char b[] = " is cool";
strcat(a,b);