Anyone ever confused by Array#slice! method?

ruby-talk
1

I just realized a minute ago why every time I
use the slice! method, one or two of my neurons
misfire.

All “bang” methods modify the receiver (though
the converse is not true – let’s not start
that one up again).

And most of them return that modified receiver…
but not the slice! method.

I see why this is, and I’m not complaining.

And of course, now that I know why it confuses
me, it never will again. Nice feeling! :slight_smile:

Just for those who are keeping score, here’s
some Ruby-core trivia:

  1. The String#slice! method works the same way
    as Array#slice!, thank goodness (and Matz).

  2. Offhand I don’t see any other bang methods
    in the core that behave that way.

  3. Some bang methods return nil if the object is
    not actually changed: gsub!, delete!, others.

  4. Now here’s a trivia question. What bang method
    appears in two different core modules and (it
    could be argued) does not really change its
    receiver? (OK, in a way it does. Don’t quibble with
    me.)

Just some midnight ramblings. Ignore at your leisure.

Cheers,
Hal

2

Hi,

  1. Some bang methods return nil if the object is
    not actually changed: gsub!, delete!, others.

All but reverse!, sort!, and exit!

  1. Now here’s a trivia question. What bang method
    appears in two different core modules and (it
    could be argued) does not really change its
    receiver? (OK, in a way it does. Don’t quibble with
    me.)

exit! does not modify anything. Its ! means “more dangerous” than non
bang version.

						matz.
···

In message “Anyone ever confused by Array#slice! method?” on 03/03/27, “Hal E. Fulton” hal9000@hypermetrics.com writes:

3

But of course you know all this, Matz. :slight_smile:

I didn’t mean to induce you to reply to
this. But thanks.

Hal

···

----- Original Message -----
From: “Yukihiro Matsumoto” matz@ruby-lang.org
To: “ruby-talk ML” ruby-talk@ruby-lang.org
Sent: Thursday, March 27, 2003 1:44 AM
Subject: Re: Anyone ever confused by Array#slice! method?

  1. Some bang methods return nil if the object is
    not actually changed: gsub!, delete!, others.

All but reverse!, sort!, and exit!

  1. Now here’s a trivia question. What bang method
    appears in two different core modules and (it
    could be argued) does not really change its
    receiver? (OK, in a way it does. Don’t quibble with
    me.)

exit! does not modify anything. Its ! means “more dangerous” than non
bang version.