C语言中结构体的初始化例子：
struct point
{
int x;
int y;
int z;
}
//常规写法
struct point pt1 = {100, 300, 200};
//初始化个数少于实际个数时，只初始化前面的成员
struct point pt2 = {400};
struct point pt3 = (struct point){100, 200, 300};
//网上说这叫乱序初始化,C99加的。
struct point pt4 = {
.y = 100,
.x = 400,
.z = 0
};
//因为是初始化，如果向下面这样赋值就错了：
//struct point pt4;
//pt4 = {100,200,300};
//pt4 = {.z = 100};