Bug #18241: Question on String Concatentation Documentation

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: DONE

[hernanat (Anthony Hernandez)]

Hello,

I noticed that the documentation for << and concat both state that the result of each operation is a new string.

However, while doing some experimenting myself I noticed that this doesn't seem to be the case. The result has the same object id and memory address as the initial string.

I also noticed that the underlying C code fore both of these does seem to return the original string pointer at the end.

Is this a documentation issue, or is there something else going on that I'm missing? If the former, I'm happy to put up a PR to fix. If it's the latter, I'd appreciate any explanation.

Thanks

Anthony

[hernanat (Anthony Hernandez)]

edit: to be clear, I'm making a distinction between "new string" in the contents-sense, and "new string" in the memory location sense.

For example, the << operation on Array inserts an array entry and returns self, which is why I was initially confused when I saw that the result of String#<< was a new string.

[jeremyevans0 (Jeremy Evans)]

• Tracker changed from Misc to Bug
• Backport set to 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN

This is a documentation bug. Both String#<< and String#concat mutate and return the receiver. I'll fix this shortly.

• Status changed from Open to Closed

Applied in changeset git|c6706f15af123bdbb3b39a21903d85c78462d047.

---

Fix documentation for String#{<<,concat,prepend}

These methods mutate and return the receiver, they don't create
and return a new string.

Fixes [Bug #18241]

[mame (Yusuke Endoh)]

• Has duplicate Bug #18261: String#prepend inconsistent documentation added

[mame (Yusuke Endoh)]

• Backport changed from 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN to 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: REQUIRED

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: REQUIRED to 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: DONE

ruby_3_0 62a33dfa168504f8ee77d493979e66616ebe1da8 merged revision(s) c6706f15af123bdbb3b39a21903d85c78462d047.