def foo
#bar = nil
if true
bar = 1
else
bar = 2
end
bar #<-- shouldn't this refer to nil since the bar from the if statement is removed from the stack?
end
puts foo # prints "1"
I always thought you had to make a temporary variable and define it as nil or an initial value so that variables defined inside an if/else statement would persist outside the scope of the if/else statement and not disappear off the stack?? Why does it print 1 and not nil?
Variables are local to a function, class or module defintion, a proc, a block.
In ruby if is an expression and the branches don't have their own scope.
Also note that whenever the parser sees a variable assignment, it will create a variable in the scope, even if that code path isn't executed:
def test
if true
a = 1
end
puts a
end
test
# Will print 1
It's bit similar to JavaScript, though it doesn't hoist the variable to the top of the scope:
def test
puts a
a = 1
end
test
# NameError: undefined local variable or method `a' for ...
So even if what you were saying were true, it still wouldn't be nil.
nil.
var keyword but not for const and let which have become the recommended ways to define variables there.