Copying strings

ruby-talk
1

I can't believe this hasn't been answered a thousand times, but I can't
seem to find the answer in the group archive.

I am parsing a string into @text (i.e. abc.def) I want to save the
part before the dot into @firstpart . For example:

               @text << "a"
               @text << "b"
               @text << "c" next char is "." so @firstpart = @text
then @text << "."
               @text << "d", etc

The problem is, this doesn't work. @firstpart apparently is a
pointer to @text and continues to receive the characters. Freezing
@firstpart doesn't work because then @text << produces a freeze error.
  There doesn't appear to be a "copy" method for string, so how do I do
this?

Sometimes the obvious eludes us....

Bill

2

WoodHacker wrote:

I can't believe this hasn't been answered a thousand times, but I can't
seem to find the answer in the group archive.

I am parsing a string into @text (i.e. abc.def) I want to save the
part before the dot into @firstpart . For example:

why not

'abc.def'.scan(/(.+)\./)[0]

?

Peter

···

__
http://www.rubyrailways.com

3

WoodHacker wrote:

I can't believe this hasn't been answered a thousand times, but I can't
seem to find the answer in the group archive.

I am parsing a string into @text (i.e. abc.def) I want to save the
part before the dot into @firstpart . For example:

               @text << "a"
               @text << "b"
               @text << "c" next char is "." so @firstpart = @text
then @text << "."
               @text << "d", etc

The problem is, this doesn't work. @firstpart apparently is a
pointer to @text and continues to receive the characters. Freezing
@firstpart doesn't work because then @text << produces a freeze error.
  There doesn't appear to be a "copy" method for string, so how do I do
this?

Sometimes the obvious eludes us....

Bill

Your code sample doesn't run at all. Here's one that does.

text = ""
text << "a"
text << "b"
text << "c"
first_part = text.dup
text << "."
text << "d"

p first_part

4

dup did the trick! Thanks a million

bill

William James wrote:

···

WoodHacker wrote:
> I can't believe this hasn't been answered a thousand times, but I can't
> seem to find the answer in the group archive.
>
> I am parsing a string into @text (i.e. abc.def) I want to save the
> part before the dot into @firstpart . For example:
>
> @text << "a"
> @text << "b"
> @text << "c" next char is "." so @firstpart = @text
> then @text << "."
> @text << "d", etc
>
> The problem is, this doesn't work. @firstpart apparently is a
> pointer to @text and continues to receive the characters. Freezing
> @firstpart doesn't work because then @text << produces a freeze error.
> There doesn't appear to be a "copy" method for string, so how do I do
> this?
>
> Sometimes the obvious eludes us....
>
> Bill

Your code sample doesn't run at all. Here's one that does.

text = ""
text << "a"
text << "b"
text << "c"
first_part = text.dup
text << "."
text << "d"

p first_part