Question

I have a method to calculate the exponent, but it doesnt like the c := c * a. If i do something like c := a. it works and im unsure why its behaving this way when i try and do c := c *a.. Im new to Smalltalk, so maybe its just something im missing. Im using Pharo as my implementaton.

testPow: i1 exp: i2
    "Testing exponent. i1 and i2 are integers, we calculate and then return the value as a Church numeral"
    | a b c |

    a := i1.
    b := i2.

        1 to: b do: [ :i |
      c:= c*a.
    ].
^c.

Answer 1

You need to initialise c before using it. With your statement:

c := a

it works because a has a value. With:

c := c * a

it won’t work because the first time through the loop, c will not be initialised to anything useful.

Just change your initialisation section to:

a := i1.
b := i2.
c := 1.