-- simple construct
if logicalCondition then conditionWasTrue()
                    else conditionWasFalse()

-- multi-line is ok too
if logicalCondition
then
  conditionWasTrue()
else
  conditionWasFalse()

-- using block stuctures
if logicalCondition then do
  conditionWasTrue()
  ...
  end
else do
  conditionWasFalse()
  ...
  end

-- if/else if...
if logicalCondition1 then do
  condition1WasTrue()
  ...
  end
else if logicalCondition2 then do
  condition2WasTrue()
  ...
  end
else do
  conditionsWereFalse()
  ...
  end