Shorter form?

ruby-talk
1

Hi
How can i compress
p a, (b == 5 ? 4 : 3 ), c
if i dont need the last part : 3 ?
Thanks
Berg

2

You can write (4 if b == 5).

If the condition evaluates to false, the expression under parenthesis will
evaluate to nil. If this is a call to puts, it will print a blank line. If
that is not OK you can do:

p *[a, (4 if b == 5), c].compact

So, this builds an array with the arguments you want to pass to p. The
compact call removes eventual Nils. The * operator (splash op) expands the
array elements as actual arguments of the method call. Pretty ugly, though,
and more verbose than your original version.

Samuel B

3

p a
p b if b==5
p c

···

On Sat, Feb 13, 2016 at 9:41 PM, A Berger <aberger7890@gmail.com> wrote:

p a, (b == 5 ? 4 : 3 ), c

4

Thanks
( @botp: qu not "who do I expand"! :wink:

···

Am 13.02.2016 15:08 schrieb "Samuel Brandão" <gb.samuel@gmail.com>:

You can write (4 if b == 5).

If the condition evaluates to false, the expression under parenthesis will
evaluate to nil. If this is a call to puts, it will print a blank line. If
that is not OK you can do:

p *[a, (4 if b == 5), c].compact

So, this builds an array with the arguments you want to pass to p. The
compact call removes eventual Nils. The * operator (splash op) expands the
array elements as actual arguments of the method call. Pretty ugly, though,
and more verbose than your original version.

Samuel B

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5

To skip the `compact` call, use:

  p a, *(4 if b == 5), c

the unary `*` operator turns non-array values (`4`) into one argument,
`nil` into zero arguments.

···

On Sat, 2016-02-13 at 16:05 +0100, A Berger wrote:

> p *[a, (4 if b == 5), c].compact