Flow Control

Goby supports several ways to do flow control, like:

• if statement
• break statement
• case statement
• while statement

If Statement

Unlike Ruby, Goby only supports one way to write if statement:

if foo
  bar
end

bar if foo # Not allowed

Also, Goby also support both else and elsif keywords.

if false
  foo
elsif true
  bar
else
  buz
end

Just like assign statement, if statement can also used as expression, which just like Ruby. And the default return value of if statement is nil:

a = if true
  10
end

puts(a) #=> 10

b = if false
  10
end

puts(b) #=> nil

break Statement

def foo(tail)
  (5..tail).each do |t|
    if t % 2 == 0 && t % 5 == 0
      puts "ouch!"
      break
    else
      puts t
    end
  end
  puts "out of the block"
end

foo 20
#=> 5 6 7 8 9
#=> ouch!
#=> out of the block

case statement

def foo(str)
  case str
  when "Elf"
    puts "You might be Aragorn II!"
  when "Aragorn"
    puts "Long time no see, Aragorn!"
  when "Frodo", "Sam", "Gandalf"
    puts "One of us!"
  else
    puts "You're not yourself"
  end
end

case, when, else can be used.

while statement

decr = 10
while decr do
  if decr < 1
    break
  end
  puts decr
  decr -= 1
end

while, conditional and a do/end block can be used for a loop