Arithmetic Constants

The format for arithmetic constants is:

number 
or
base#number 

where base is a whole number between 2 and 36, and number is any non-negative integer. If not specified, the default base is 10. The arithmetic base of a variable can be set with the typeset –in command, or by prepending base# to the value. In this example, variable X is set to 5 in base 2 using both formats:

					$ typeset —i2 X=5
				

or

					$ typeset —i X=2#101
				

When variable X is expanded, the value is written in base 2:

					$ print $X
					2#101
				

If you want to display the value of X in another base, just reset the base with the typeset –in command. Here it is reset to base 3:

					$ typeset —i3 X
					$ print $X
					3#12
				

Arithmetic can be performed on numbers with different bases. Here is an example - X is set to 7 in base 2:

					$ typeset —i X=2#111
				

Y is set to 8 in base 5:

					$ typeset —i5 Y=8
				

and Z is set to base 16:

					$ typeset —i16 Z
				

Now, X and Y are added together and the result is put in Z:

					$ Z=X+Y
					$ print $Z
					16#f
				

We could convert the result to octal by resetting the base of Z using the typeset –in command like this:

					$ typeset —i8 Z
					$ print $Z
					8#17