converting a number in base b to a number in base 10 using ^^ in Mathematica

*To*: mathgroup at yoda.physics.unc.edu*Subject*: converting a number in base b to a number in base 10 using ^^ in Mathematica*From*: gaylord at ux1.cso.uiuc.edu*Date*: Thu, 26 Mar 1992 04:44:33 -0600

on p. 537 of the second edition of the bible it says that to go from a number 'mmm' in base b to a number in base 10 use b^^mmm eg., 2^^101 5 writing a program to do this, base2tobase10conversion[n_Integer] := 2^^n however, when this is entered into the global rule base, i got base2tobase10conversion[n_Integer] := 2^^n General::digit: Digit at position 1 in n is too large to be used in base 2. hoping it was one of those messages that don't mean much, i tried to run the program base2tobase10conversion[101] $Failed what's going on apparently is that M wants the quantity to the right of ^^ to be an integer. i tried to use Hold to avoid the problem but it doesn't help. i then tried : 101 101 2^^% Syntax::sntxf: "2^" cannot be followed by "^%" it seems that the ^^ operator absolutely insists on being immediately followed by an integer. can someone suggest another way (there must be; there's always another way to do almost everything in M) to convert a number in base b to base 10 other than using ^^. i find it hard to believe that M does not have a built-in function for doing this but i can't find it in the book.