On Thursday 21 April 2005 9:40 pm, Synthetic Cartoonz wrote:
A pointer is just the numeric address of a memory location . Starting at 0 and going up from there . (I've never seen an architecture that specifies negative addresses, though I guess anything is possible.) In most implementations assigning the integer value 0 to a pointer produces the expected result. Typically, the 0 (as integer) is promoted to whatever storage unit a pointer is. You may see a compiler warning about the type conversion. Pointers are generally unsigned. Many architectures do use hexadecimal 'F" in high-order positions.
Most architectures do not permit user mode addresses at 0, but some do.
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Jerry Feldman