Question

const char *pointerStr[]=
{
   "BEST123,      ",     // 0x00
   "Best2233,     ",     // 0x01
   "ABCDEFGH,     ",     // 0x02
   "123456,     ",     // 0x03
   "helloworld,     "     // 0x04
};
typedef struct
{
   char value;
   char name[40]; 
}StrInfo;

typedef struct
{
   int regMax;
   StrInfo info[60];   
} structNew;

void main()
{
  int i;
  structNew  pret;
for ( i=0;i<5;i++)
{     
  printf("PointerStr size of %dth %d \n",i,sizeof(pointerStr[i]));
  printf("pret size of %dth %d \n",i,sizeof(pret.info[i].name));
}
}

The above program produce the result of

PointerStr size of 0th 4 
pret size of 0th 40 
PointerStr size of 1th 4 
pret size of 1th 40 
PointerStr size of 2th 4 
pret size of 2th 40 
PointerStr size of 3th 4 
pret size of 3th 40 
PointerStr size of 4th 4 
pret size of 4th 40 

If I want to know the size of each and every string in PointerStr then how to find it? Is it possible only using strlen ? do we have some other way ? How this variable length array is stored in memory ?
The result is becoz that pointerStr is pointer variable and its size is always 4. Please correct me if I am wrong.

Answer 1

The length of a C string is implicit: it is determined by where the terminating '\0' is in the string, so you will need a function like strlen to determine the length of a string.

The values ‘returned’ by sizeof are determined by the compiler by looking at the type of the data, instead of the data itself.