自写字符串转换成整型函数

eg1：

typedef struct

{

    char Ch;

    int  In;

}CIMAP;

const CIMAP CiMap[] =

{

    {'0', 0},    {'1', 1},    {'2', 2},    {'3', 3},

    {'4', 4},    {'5', 5},    {'6', 6},    {'7', 7},

    {'8', 8},    {'9', 9}

};int main(){ char a[] = "1234"; int i = 0; int j = 0; int b = 0; int mul = 1;

 for(j = 3;j>=0;j-- ) {  for(i = 0;i<sizeof(CiMap)/sizeof(CiMap[0]);i++)  {

   if(a[j] == CiMap[i].Ch )   {       b = b+mul*CiMap[i].In;    mul = mul*10;    }  } } printf("b = %d/n",b);

 printf("x = %d/n",atoi(a));

 return 0;}

 

 

eg2：

int main(){ char a[] = "01023456789"; int i = 0; int b = 0; int mul = 1; int j = 0; j = (sizeof(a)/sizeof(a[0]))-2 ; for(i = j;i>=0;i--) {  b = b+mul*(a[i]-'0');  mul = mul*10; }

 printf("b = %d/n",b);

 return 0;}