解引用运算符

解引用运算符（dereference operator）或称间址运算符（indirection operator）。C语言编程语言家族中常表示为"*" (一个星号)，为单元运算符，作用于1个指针变量，返回该指针地址的等效左值。这被称为指针的解引用。例如：

int x;
int p; // is used in the declaration:
// p is a pointer to an integer, since (after dereferencing),
// *p is an integer
x = 0;
// now x == 0
p = &x; // & takes the address of x
// now p == 0, since p == &x and therefore p == x
*p = 1; // equivalent to x = 1, since p == &x
// now *p == 1 and x == 1

在C语言中，&是解引用运算符的逆运算。因此&s等价于s。例如：

p = &s; // the address of s has been assigned to p; p == &s;
// *p is equivalent to s

结构s的成员a的值可表示为s.a。若指针p指向s (即p == &s), s.a等价于(*p).a，也可用结构解引用运算符作为语法糖缩写表示为p->a：

p = &s; // the address of s has been assigned to p; p == &s;
// s.a is equivalent to (*p).a
// s.a is equivalent to p->a
// (*p).a is equivalent to p->a

Unix的外壳脚本以及一些工具软件如Makefile中，美元符"$"为解引用运算符，用于把变量名字转译为其内容。
参见
*结构解引用运算符
参考文献