Way to split a string based on fixed length?

[Wayne Molina]

This is probably a newb question but I can't seem to figure it out. I
have a string I'm trying to parse, that is done via a fixed length
format - it needs to be split on every 8th character in order for me to
get a proper array list of it so I can do some additional operations on
it.

The string is something like this: '0000000N0000000N0000000N0000000N'
and I need it to be an array containing something like: ['0000000N',
'0000000N', '0000000N', '0000000N'].

Is there a ruby method I can use to split the single string into groups
of x number of characters, when there is no delimiter?

 

[James Gray]

This is probably a newb question but I can't seem to figure it out. I
have a string I'm trying to parse, that is done via a fixed length
format - it needs to be split on every 8th character in order for me
to
get a proper array list of it so I can do some additional operations
on
it.

The string is something like this: '0000000N0000000N0000000N0000000N'
and I need it to be an array containing something like: ['0000000N',
'0000000N', '0000000N', '0000000N'].

Is there a ruby method I can use to split the single string into
groups
of x number of characters, when there is no delimiter?

Sure, you can use a regular expression for this:
=> ["0000000N", "0000000N", "0000000N", "0000000N"]

James Edward Gray II

 

[john.slobbe]

You can use:

string.unpack "A8A8A4A2" # => ["0000000N", "0000000N", "0000", "00"]

Regards, John.

 

[Wayne Molina]

Awesome! Thanks much!

 

[Craig Demyanovich]

[Note: parts of this message were removed to make it a legal post.]

I thought String#split with a regex might do it, but I'm not sure why it
returns an array with empty strings in it. So I tried String#scan. It works,
but since we're grouping into runs of eight characters, it returns an array
of arrays of results. No problem, we can just use Array#flatten to take care
of that. Here's IRB output showing the approaches:

'0000000N0000000N0000000N0000000N'.split(/(\w{8})/) => ["", "0000000N", "", "0000000N", "", "0000000N", "", "0000000N"]
'0000000N0000000N0000000N0000000N'.scan(/(\w{8})/) => [["0000000N"], ["0000000N"], ["0000000N"], ["0000000N"]]
'0000000N0000000N0000000N0000000N'.scan(/(\w{8})/).flatten

=> ["0000000N", "0000000N", "0000000N", "0000000N"]

Regards,
Craig

 

[Craig Demyanovich]

[Note: parts of this message were removed to make it a legal post.]

D'oh, GMail didn't update the conversation while I was replying. Anyway, you
have some good answers.

Craig

 

[Chris Causer]

[Note: parts of this message were removed to make it a legal post.]

I thought String#split with a regex might do it, but I'm not sure why it
returns an array with empty strings in it.
[snip]=> ["", "0000000N", "", "0000000N", "", "0000000N", "", "0000000N"]

Going a bit off topic here, but I suspect the reason split adds empty
strings is because it is matching the 8 characters, splitting there, but
because you are capturing them, puts the delimiter back in the array it as
well. The gap between the 8 characters is nothing, thus "". I guess that if
you split(/\w{8}/) you'll get nothing because there will be nothing left
after removing the delimeter (unless the string isn't of length 8n, n is an
integer.)

 

[Adam Penny]

I thought String#split with a regex might do it, but I'm not sure why it
returns an array with empty strings in it. So I tried String#scan. It
works,

Don't quote me on this, but I think that would be because String#split
had a regex to define the character/group of characters that you're
interested in, so if you're defining the split as any old 8 characters
then that doesn't leave an awful lot!