结构体与指针

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结构体与指针

例程1

typedef struct{    unsigned int a;    unsigned int b;    unsigned int c;}Test_T;void main(void){    Test_T Temp;    Test_T *Test;//指向数组的指针    Test=&Temp;    Temp.a=0;    Temp.b=1;    Temp.c=2;    *(unsigned int *)((unsigned int)&(Test->a)+0)+=5;    *(unsigned int *)((unsigned int)&(Test->a)+4)+=1;    *(unsigned int *)((unsigned int)&(Test->a)+8)+=4;    printf("a=%d,b=%d,c=%d\n",Temp.a,Temp.b,Temp.c);    printf("sizeof(unsigned int)=%d\n",sizeof(int));    printf("sizeof(Test_T)=%d\n",sizeof(Test_T));    printf("&Temp.a=%d\n",&Temp.a);    printf("&Temp.b=%d\n",&Temp.b);    printf("&Temp.c=%d\n",&Temp.c);    printf("Test=%d\n",*Test);    printf("Test=%d\n",Test);    printf("Test+1=%d\n",Test+1);    printf("Test+1=%d\n",Test+2);}

输出结果

Test为指向结构体的指针，Test值为存放结构体内存的首地址，Test+1实际上指针移动了3*sizeof（unsigned int）。可以通过*Test来查询结构体中第一个成员的值
例程2

typedef struct{    unsigned int a[2];    unsigned int b;    unsigned int c;}Test_T;void main(void){    Test_T Temp;    Test_T *Test;//指向数组的指针    Test=&Temp;    Temp.a[0]=8;    Temp.b=1;    Temp.c=2;    printf("sizeof(unsigned int)=%d\n",sizeof(int));    printf("sizeof(Test_T)=%d\n",sizeof(Test_T));    printf("&Temp.a=%d\n",&Temp.a[0]);    printf("&Temp.b=%d\n",&Temp.b);    printf("&Temp.c=%d\n",&Temp.c);    printf("Test=%d\n",Test);    printf("*Test=%d\n",*Test);}

输出结果

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