c++ - '**' 在 C 中是什么意思？

Question

一个对象开头有两个星号是什么意思？

**variable

Answer 1

在声明中，它意味着它是一个指向指针的指针:

int **x;  // declare x as a pointer to a pointer to an int

使用它时，它会尊重它两次:

int x = 1;
int *y = &x;  // declare y as a pointer to x
int **z = &y;  // declare z as a pointer to y
**z = 2;  // sets the thing pointed to (the thing pointed to by z) to 2
          // i.e., sets x to 2