How Does `delete[]` Know the Size of the Array to Deallocate?

Storing Array Metadata for 'delete[]' Operation

The 'delete[]' operator in C is responsible for deallocating memory allocated for an array, but it does not explicitly require the array's size as an operand. This raises the question, "How does 'delete[]' determine the size of the array it is attempting to deallocate?"

To understand this mechanism, it is crucial to recognize the role of the memory allocator. When memory is allocated on the heap using the 'new' operator, the memory allocator manages the allocated memory and tracks its size. This information is typically stored in a "head" segment immediately before the allocated memory.

In the case of arrays, the head segment contains the number of elements in the array, allowing the 'delete[]' operator to determine the size of the array it needs to deallocate. This standardization enables the 'delete[]' operator to successfully free the correct amount of memory even without the explicit specification of the array's size.

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