How can I delete one element from an array by value

Borrowing from Travis in the comments, this is a better answer:

I personally like [1, 2, 7, 4, 5] - [7] which results in => [1, 2, 4, 5] from irb

I modified his answer seeing that 3 was the third element in his example array. This could lead to some confusion for those who don't realize that 3 is in position 2 in the array.

I'm not sure if anyone has stated this, but Array.delete() and -= value will delete every instance of the value passed to it within the Array. In order to delete the first instance of the particular element you could do something like

arr = [1,3,2,44,5]
arr.delete_at(arr.index(44))

#=> [1,3,2,5]

There could be a simpler way. I'm not saying this is best practice, but it is something that should be recognized.

Another option:

a = [2,4,6,3,8]

a -= [3]

which results in

=> [2, 4, 6, 8] 

I think I've figured it out:

a = [3, 2, 4, 6, 3, 8]
a.delete(3)
#=> 3
a
#=> [2, 4, 6, 8]