Octal and Hexadecimal

Normally integers are displayed in decimal. Sometimes it is more useful to use octal (base 8) or hexadecimal (base 16). The way in which such constants are written is not the same on all computers, in fact most won't allow octal (but the VMS will). For example the hexadecimal number 1A (i.e. the decimal number 26) is written:-

Z1A (IBM)

'1A'X (VMS)

There is no octal constant on the IBM; on the VMS the octal number 11 (i.e. the decimal number 9) is written:-

'11'O

During I/O the format descriptor Om.n is used for octal and Zm.n for hexadecimal - see section 9.2.

Exercise 18

Write a program to type out the integers -1000, -100, -1, 0, 1, 100 and 1000 in a table in decimal, octal and hexadecimal.

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