where does 0x come from? [duplicate]

This question already has answers here: Closed 12 years ago.

Possible Duplicate:

Why are Hexadecimal Prefixed as 0x?

I just saw a comment a friend of mine made:

3x12=36
2x12=24
1x12=12
0x12=18

Which made me wonder..

Why did they choose 0x as prefix for hexadecimal numbers? Is there any history be开发者_如何转开发hind this decision?

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I think, because x comes from hex and 0 is to indicate that it is a number.

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0x means the number is probably hexadecimal. This applies in C/C++, and probalby other languages.

His comment is a joke. he starts with multiplication tables for the number 12, but when he gets to 0 he implies that 0x is not "0 multiplied by...", but instead is "hexadecimal" so 12 in hex is 18 in decimal.

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It's a joke on HEX numbers from WIKIPEDIA.

The first three are interpreted as multiplication, but in the last, "0x" signals Hexadecimal interpretation of 12, which is 18.

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'0x' means that the number that follows is in hexadecimal. It's a way of unambiguously stating that a number is in hex, and is a notation recognised by C compilers and some assemblers