Why does a memory address start with 0x?

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Why are Hexadecimal Prefixed as 0x?

Memory addresses are often notated as a hexidecimal value prefixed with 0x. E.g:

> new.env()
<environment: 0x21d36e0>

Does the 0x part mean anything? Where does this notation come from? Is any other value possible instead of 0x?

score 28 · Accepted Answer · answered Jul 13 '12 at 09:28

28

The 0x is just a notation to let you know the number is in hexadecimal form.

Same as you'd write 042 for an octal number, or 42 for a decimal one.

So - 42 == 052 == 0x2A.

answered Jul 13 '12 at 09:28

Luchian Grigore

7

The "0" helps the parser know that its dealing with a (constant) number and the "x" stands for hex. – Jesse Good Jul 13 '12 at 09:42
1

@JesseGood....then how parser know in case of Decimal number because it is not preceded by 0. – Tejendra Jul 13 '12 at 10:06
2

@Tejendra it knows by exclusion. If it's not `0` or `0x`, it's decimal :) – Luchian Grigore Jul 13 '12 at 10:32
@LuchianGrigore...thnx for the clarification :) – Tejendra Jul 13 '12 at 10:35

score 7 · Answer 2 · answered Jul 13 '12 at 09:30

7

Memory address is usually represented in Hexadecimal Form, 0x is just a notation for Hex number.

answered Jul 13 '12 at 09:30

Tejendra

2 Answers2