Do I lack understanding or arrays?

ruby-talk
1

I'm doing the pascal quiz on rubyquiz.com, but I'm finding that I'm
having trouble assigning a value to my array.

I've assigned it like this:

      pyramid_lvl[level][i] =\
          ( (pyramid[level-1][i-1]).to_i \
          + (pyramid[level-1][i] ).to_i )

and like this:
      num1 = pyramid[level-1][i-1].to_i
      num2 = pyramid[level-1][i].to_i
      ans = num1+num2
      pyramid_lvl[level][i] = [ans]

Both give me this error message:
undefined method `[]=' for 1:Fixnum (NoMethodError)

Am I getting this problem because I don't understand how arrays work
and it's simply a matter of operations, or am I having some serious
logical problem preventing correctness.

2

Hakusa@gmail.com wrote:

I'm doing the pascal quiz on rubyquiz.com, but I'm finding that I'm
having trouble assigning a value to my array.

I've assigned it like this:

      pyramid_lvl[level][i] =\
          ( (pyramid[level-1][i-1]).to_i \
          + (pyramid[level-1][i] ).to_i )

and like this:
      num1 = pyramid[level-1][i-1].to_i
      num2 = pyramid[level-1][i].to_i
      ans = num1+num2
      pyramid_lvl[level][i] = [ans]

Both give me this error message:
undefined method `=' for 1:Fixnum (NoMethodError)

Am I getting this problem because I don't understand how arrays work
and it's simply a matter of operations, or am I having some serious
logical problem preventing correctness.

From the error, I would venture to guess (pretty sure) that pyramid_lvl[level] contains a number, not an array (as you seem to think). I couldn't say more without reading more code.

Dan

3

Hi --

I'm doing the pascal quiz on rubyquiz.com, but I'm finding that I'm
having trouble assigning a value to my array.

I've assigned it like this:

     pyramid_lvl[level][i] =\
         ( (pyramid[level-1][i-1]).to_i \
         + (pyramid[level-1][i] ).to_i )

and like this:
     num1 = pyramid[level-1][i-1].to_i
     num2 = pyramid[level-1][i].to_i
     ans = num1+num2
     pyramid_lvl[level][i] = [ans]

Both give me this error message:
undefined method `=' for 1:Fixnum (NoMethodError)

Am I getting this problem because I don't understand how arrays work
and it's simply a matter of operations, or am I having some serious
logical problem preventing correctness.

It's just what the error says: you're trying to call the method = on
the object 1 :slight_smile: That means that pyramid_lvl[level] must be 1. So
when you do:

   pyramid_lvl[level][i] = whatever

it's like you're doing:

   1[i] = whatever

That's equivalent to a method call:

   1=(i, whatever)

and 1 has no method called = so you get an error.

I can't tell you where in your code you assigned 1 to
pyramid_lvl[level], but that appears to be what's happening.

David

···

On Mon, 28 May 2007, Hakusa@gmail.com wrote:

--
Q. What is THE Ruby book for Rails developers?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
    (See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)

4

I tested this:

pyramid_lvl[level][i] is 0
pyramid[level-1][i] is 1
pyramid[level-1][i-1] is 1

Turns out that pyramid[level-1][i] was actually nil... which makes
this a logical error, not a syntax error.

So I pretty much just waisted your time, but so long and thanks for
all the fish.

5

was actually nil

typo. I meant 0