bc: Variables

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1 2.2 Variables
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1 Numbers are stored in two types of variables, simple variables and
1 arrays.  Both simple variables and array variables are named.  Names
1 begin with a letter followed by any number of letters, digits and
1 underscores.  All letters must be lower case.  (Full alphanumeric names
1 are an extension.  In POSIX 'bc' all names are a single lower case
1 letter.)  The type of variable is clear by the context because all array
1 variable names will be followed by brackets ( [ ] ).
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1    There are four special variables, SCALE, IBASE, OBASE, and LAST.
1 SCALE defines how some operations use digits after the decimal point.
1 The default value of SCALE is 0.  IBASE and OBASE define the conversion
1 base for input and output numbers.  The default for both input and
1 output is base 10.  LAST (an extension) is a variable that has the value
1 of the last printed number.  These will be discussed in further detail
1 where appropriate.  All of these variables may have values assigned to
1 them as well as used in expressions.
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