An integer pointer is a variable that stores the address of an integer variable. Integer pointers are declared using the int* keyword. For example, the following code declares an integer pointer variable called ptr:

int* ptr;

ptr variable can store the address of any integer variable.

To assign the address of an integer variable to an integer pointer, we use the & operator. For example, the following code assigns the address of the integer variable x to the integer pointer ptr:

int x = 10;
ptr = &x;

Once the ptr pointer variable contains the address of an integer variable, we can use it to access the value of the integer variable. To do this, we use the * operator. For example, the following code prints the value of the integer variable x to the console:

printf("%d\n", *ptr);

This code will print the following output:

10

Character pointer

A character pointer is a variable that stores the address of a character variable. Character pointers are declared using the char* keyword. For example, the following code declares a character pointer variable called ptr:

char* ptr;

The ptr variable can store the address of any character variable.

To assign the address of a character variable to a character pointer, we use the & operator. For example, the following code assigns the address of the character variable c to the character pointer ptr:

char c = 'a';
ptr = &c;

Once the ptr pointer variable contains the address of a character variable, we can use it to access the value of the character variable. To do this, we use the * operator. For example, the following code prints the value of the character variable c to the console:

printf("%c\n", *ptr);

This code will print the following output:

a

Difference between integer pointer and character pointer

The main difference between an integer pointer and a character pointer is the size of the data type that they point to. An integer pointer points to an integer, which is typically 4 bytes in size. A character pointer points to a character, which is typically 1 byte in size.

 integer pointers and character pointers:

This difference in size can be seen when we try to dereference the pointers. For example, the following code will print the value of the integer pointed to by ptr:

int* ptr = NULL;

printf("%d\n", *ptr);

This code will cause a segmentation fault, because the ptr pointer is NULL and does not point to any valid memory location.

Code will not cause a segmentation fault, even though the ptr pointer is NULL:

char* ptr = NULL;

printf("%c\n", *ptr);

This is because the ptr pointer is a character pointer, and character pointers are typically initialized to the null character (\0), which is a valid character value.

Another difference between integer pointers and character pointers is that character pointers can be used to access strings. A string is a sequence of characters terminated by a null character (\0). To access the characters of a string, we can use a character pointer to iterate over the string until we reach the null character.

Code prints the characters of the string hello to the console:

char* str = "hello";

while (*str != '\0') {
  printf("%c", *str);
  str++;
}

This code will print the following output:

hello

Integer pointers cannot be used to access strings in this way.

I hope this helps to explain the difference between integer pointers and character pointers in C.