The sizeof operator returns a value of type size_t , which is an unsigned integral type defined in the C standard library (usually in <stddef.h>). This type is used to represent sizes and is guaranteed to be able to express the maximum size of any object in bytes.

• In C, sizeof returns the size in bytes of its operand, which can be a data type, variable, pointer, or expression

• The exact underlying type of size_t is an unsigned integer type, typically unsigned int or unsigned long, depending on the platform and compiler

• When printing the value returned by sizeof, the %zu format specifier is recommended as it matches the size_t type

• sizeof is an operator, not a function, and its result is determined at compile time

In summary:

• Return type: size_t (an unsigned integral type)
• Represents: The size in bytes of the operand's type or expression

This ensures that the value returned by sizeof can safely represent any object size in memory without negative values