What happens when you dereference an array in C?

What you dereference is a pointer to an array. Thus, dereferencing gives you the array. Passing an array to printf (or to any function) passes the address of the first element. You tell printf that you pass it an unsigned int ( \%u ), but actually what is passed is an int* .

How do you find the size of an array of pointers?

Find the size of an array in C using sizeof operator and pointer…

1. sizeof operator. The standard way is to use the sizeof operator to find the size of a C-style array.
2. Using pointer arithmetic. The trick is to use the expression (&arr)[1] – arr to get the array arr size.

Does sizeof work on arrays in C?

To determine the size of your array in bytes, you can use the sizeof operator: int a[17]; size_t n = sizeof(a); On my computer, ints are 4 bytes long, so n is 68. To determine the number of elements in the array, we can divide the total size of the array by the size of the array element.

How do you dereference a pointer to an array?

This is done as follows. int *ptr = &arr[0]; After this, a for loop is used to dereference the pointer and print all the elements in the array. The pointer is incremented in each iteration of the loop i.e at each loop iteration, the pointer points to the next element of the array.

How do you dereference a pointer to a pointer?

1 Answer

1. x is a pointer to a pointer to int.
2. *x yields a int* (pointer to int )
3. **x = is like *(*x) = so you first obtain the pointer to int then by dereferencing you are able to set the value at the address.

What is array Dereferencing?

Array Dereferencing is really very good feature added in PHP 5.4. With this you can directly access an array object directly of a method a functions. Now we can say that no more temporary variables in php now. As as above code you can deal with functions call also.

How does an array pointer work?

A variable declared as an array of some type acts as a pointer to that type. When used by itself, it points to the first element of the array. A pointer can be indexed like an array name.

What is the size of a pointer?

Usually it depends upon the word size of underlying processor for example for a 32 bit computer the pointer size can be 4 bytes for a 64 bit computer the pointer size can be 8 bytes.

How does sizeof array work?

The sizeof() operator returns pointer size instead of array size. The ‘sizeof’ operator returns size of a pointer, not of an array, when the array was passed by value to a function. So, the sizeof(B) expression will return value 4 or 8 (the size of the pointer in a 32-bit/64-bit system).