What does “+=” (plus equals) mean?

Question

I am doing some ruby exercises and it said I need to go back and rewrite the script with += shorthand notations.

This exercise deals primarily with lear

Answer 1

You should look for a good book about Ruby, e.g. http://pragprog.com/book/ruby3/programming-ruby-1-9

The first 150 pages cover most of the basic things about Ruby.

str = "I want to learn Ruby"

i = 0
str.split.each do |word|
  i += 1
end

puts "#{i} words in the sentence \"#{str}\""

  => 5 words in the sentence "I want to learn Ruby"

Answer 2

+= is a shorthand operator.

someVar += otherVar

is the same as

someVar = someVar + otherVar

Answer 3

Expressions with binary operators of the form:

x = x op y

Can be written as:

x op= y

For instance:

x += y   # x = x + y
x /= y   # x = x / y
x ||= y  # x = x || y (but see disclaimer)

However, be warned that ||= and &&= can behave slightly ... different (most evident when used in conjunction with a hash indexer). Plenty of SO questions about this oddity though.

Happy coding.

Answer 4

Not an ruby expert but I would think that it either appends to an existing String or increments an numeric variable?