Type conversion

Ruby
1

So there is an to_s for strings and a to_i for integers. However, if I
have an array of integers and I want to grab one, I get back and ASCII
character. For example, when I grab a 1 from the array it returns a 49 -
but I wanted the one! How do I convert it back to its integer
want-to-be? Thanks,

~S

P.S. I imagine this is probably an easy solution but, I am a ruby
newbie.

2

Shandy N. wrote:

So there is an to_s for strings and a to_i for integers. However, if I
have an array of integers and I want to grab one, I get back and ASCII
character.

Are you sure you have an array of integers?

Show some code.

For example, when I grab a 1 from the array it returns a 49 -
but I wanted the one! How do I convert it back to its integer
want-to-be? Thanks,

This works for me:

Create int array, 11 to 19

the * expands the range into an array

a = *11…19

print it to see what we have

p a

See what we have at the first location

p a[0] # I get 11

–
James B.

“Take eloquence and wring its neck.”

  • Paul Verlaine
3

On Jul 17, 2007, at 5:05 PM, Ian W. wrote:

~S
irb(main):005:0> i[0].class
–
Posted via http://www.ruby-forum.com/.

arr = “1234”

Will only give you a string.
You need :
arr = Array.new
arr << 1
arr << 2
…
OR
arr = [1,2,3,4,]

At the command line, use ri:
ri Array
ri ‘[]=’
ri ‘Array#[]=’
ri ‘String#[]=’

4

Shandy N. wrote:

So there is an to_s for strings and a to_i for integers. However, if I
have an array of integers and I want to grab one, I get back and ASCII
character. For example, when I grab a 1 from the array it returns a 49 -
but I wanted the one! How do I convert it back to its integer
want-to-be? Thanks,

~S

P.S. I imagine this is probably an easy solution but, I am a ruby
newbie.

Shandy, Perhaps this helps. Note the difference between 004 and 006

irb(main):003:0> i = “1234”
=> “1234”
irb(main):004:0> i[0]
=> 49
irb(main):005:0> i[0].class
=> Fixnum
irb(main):006:0> i[0,1]
=> “1”
irb(main):007:0> i[0,1].class
=> String
irb(main):008:0> i[0,1].to_i
=> 1
irb(main):009:0> i[0,1].to_i.class
=> Fixnum

Good luck from another newbie.
Ian

5

Shandy N. wrote:

char = card_num[i].to_i

All I wanted to do was to pick out a single character (a digit) from
that string and perform some calculations on it. But by just saying [i]
I got a 57 value when I wanted the 9 value. When I said [i…i] I got the
9 value. Thanks for all your help,

~S

Card_num[i] is returning the character value at position i.

card_num[i].chr will return the character at position i

card_num[i].chr.to_i will return the integer value of the character

card_num[i].type => Fixnum

card_num[i…i].type => String and is why card_num[i…i].to_i worked

6

Sorry about not giving code. I did finally get it to work, but here is
what I had to do:

card_num = “123456789”
c = 0

char = card_num[i…i].to_i

before I had:

char = card_num[i].to_i

All I wanted to do was to pick out a single character (a digit) from
that string and perform some calculations on it. But by just saying [i]
I got a 57 value when I wanted the 9 value. When I said [i…i] I got the
9 value. Thanks for all your help,

~S

7

On Jul 18, 2007, at 10:51 AM, Shandy N. wrote:

char = card_num[i].to_i

All I wanted to do was to pick out a single character (a digit) from
that string and perform some calculations on it. But by just saying
[i]
I got a 57 value when I wanted the 9 value. When I said [i…i] I
got the
9 value. Thanks for all your help,

It’s a bit late, I guess, but did you consider something like:

"123456789"[-1] - ?0 # => 9

Regards, Morton