Method to call the object if the object exists

Question

Is there a more elegant way to write this?

@on_connection_callback.call() if @on_connection_callback

It has to reference @on_connection_callback twice, which annoys me.

+3

ruby

Undistraction Jan 25. 13 at 14:04

source to share

5 answers

VB9-UANIC · Answer 1 · 2013-01-25T14:20:47+0000

you can write it like

@on_connection_callback.call() rescue nil

Dave newton · Answer 2 · 2013-01-25T14:28:06+0000

I like things like the "andand" gem , which allows:

@on_connection_callback.andand.call()

There are other options, such as different implementations try

.

sawa · Answer 3 · 2013-01-25T14:28:19+0000

@on_connection_callback.instance_eval{call if self}

or

->p{p.call if p}.call(@on_connection_callback)

the Tin Man · Answer 4 · 2013-01-25T14:56:12+0000

@on_connection_callback.call() if @on_connection_callback

great, and actually the fastest way to test. I recently did a benchmark test proving that the above is slightly faster than:

@on_connection_callback && @on_connection_callback.call()

megas · Answer 5 · 2013-01-25T15:04:09+0000

Use this little gem :

tryit { @on_connection_callback.call() }