What does "+=" (plus equals) mean in Ruby?
ruby
Solution
num += -1
is an equivalent of
num = num + -1
or, for this example
num = num - 1
which, in turn, can be written as
num -= 1
Problem
I'm going through a Ruby tutorial and I can't grasp the += statement. Google isn't helping, "Ruby +=" only searches for "Ruby". Help is appreciated. Sample: ``` num = -10 num += -1 if num < 0 puts num #=> -11 ```