How Can I Determine the Size of an Array Passed as a Pointer in C ?

Determining Array Size with a Pointer

In C , where an array decayers to a pointer, retrieving the array's size from the pointer can be challenging.

Problem

Finding the size of an array passed as a pointer requires additional information, as the pointer itself does not contain this data.

Solution

To resolve this issue, two approaches are available:

1. Passing Size Information as an Argument: Send the size of the array as an additional parameter to the function. For example:

   func(int* array, size_t arraySize);

2. Utilizing Array Syntax: If the array's size is known in advance, passing it as a fixed-sized array achieves the same effect:

   func(int array[5]);

Explanation

The pointer decay rule allows arrays to behave like pointers, but this does not imply that they are inherently pointers. They simply decay to pointers when passed as function arguments.

To determine the array's size from a pointer, additional size information must be provided. This can be achieved by explicitly passing the size as an argument or utilizing the array syntax, which includes the size information within the declaration.

The above is the detailed content of How Can I Determine the Size of an Array Passed as a Pointer in C ?. For more information, please follow other related articles on the PHP Chinese website!