String and Pointer

The string itself act as a pointer.

The string name is a pointer to the first character in the string.




string name == &string[0]

As we all know, the string is a character array which is terminated by the null '\0' character.

Example

char str[6]="Hello";

Where,

str is the string name and it is a pointer to the first character in the string. i.e. &str[0].

Similarly, str+1 holds the address of the second character of the string. i.e. &str[1]

To store "Hello", we need to allocate 6 bytes of memory.

5 byte for "Hello"

1 byte for null '\0' character.


string character address



Let's print each character address of the string 'str'

Example

#include<stdio.h>

int main()
{
    char str[6] = "Hello";
    int i;

    //printing each char address
    for(i = 0; str[i]; i++)
         printf("&str[%d] = %p\n",i,str+i);

    return 0;
}

%p format specifier is used to printing the pointer address.





str[i] == *(str+i)

str[i] will give the character stored at the string index i.

str[i] is a shortend version of *(str+i).

*(str+i) - value stored at the memory address str+i. (base address + index)


string character value



Let's print each character of a string using *(str+i)

Example

#include<stdio.h>

int main()
{
    char str[6] = "Hello";
    int i;

    //printing each char value
    for(i = 0; str[i]; i++)
         printf("str[%d] = %c\n",i,*(str+i)); //str[i] == *(str+i)

    return 0;
}


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