c++ - 如何在声明后设置 const char*？

Question

//v is a random number 0 or 1
const char *str;
//str = 48 + v; //how to set??  

我尝试了 memcpy 和 sprintf 并遇到了“const char*”的问题

我想将“str”设置为“v”定义的 0 或 1。但必须是“const char*”类型

Answer 1

我的猜测是您想在第一次声明后更改 const char 的值，对吗？虽然您不能直接更改 const char* 的值，但您可以将指针值更改为普通变量。例如在这里查看此页面:Constants in C and C++

这是使用指针更改 const 值可以做和不能做的事情:(从上面的链接采用):

const int x;      // constant int
x = 2;            // illegal - can't modify x

const int* pX;    // changeable pointer to constant int
*pX = 3;          // illegal -  can't use pX to modify an int
pX = &someOtherIntVar;      // legal - pX can point somewhere else

int* const pY;              // constant pointer to changeable int
*pY = 4;                    // legal - can use pY to modify an int
pY = &someOtherIntVar;      // illegal - can't make pY point anywhere else

const int* const pZ;        // const pointer to const int
*pZ = 5;                    // illegal - can't use pZ to modify an int
pZ = &someOtherIntVar;      // illegal - can't make pZ point anywhere else

这也适用于您尝试做的字符。