diiferent between * and & in c

The '*' symbol in C is used to declare a pointer variable and to dereference a pointer to access the value it points to. On the other hand, the '&' symbol is used to obtain the address of a variable.

1. Declaration of a Pointer:

int *ptr;

Here, '*' is used to declare a pointer to an integer.

1. Dereferencing a Pointer:

int x = 10;
int *ptr = &x;
int value = *ptr;

Here, '*' is used to dereference the pointer 'ptr' to obtain the value stored at the address it points to.

1. Function Parameters:

void myFunction(int *ptr) {
    // Function code
}

In function parameters, '*' is used to declare a pointer parameter, allowing the function to receive the address of a variable.

1. Address of Operator:

int x = 20;
int *ptr = &x;

The '&' symbol is used to get the address of the variable 'x' and assign it to the pointer 'ptr'.

1. Pointers and Arrays:

int arr[] = {1, 2, 3, 4, 5};
int *ptr = arr;

Here, '*' is used to declare a pointer 'ptr' that points to the first element of the array 'arr'.

1. Dynamic Memory Allocation:

int dynamicPtr = (int )malloc(sizeof(int));

The '*' symbol is used to declare a pointer that will hold the address of a dynamically allocated memory block.

In summary: - '*' is used to declare a pointer and to dereference a pointer. - '&' is used to obtain the address of a variable.