-- If executes then first block when condition is true
if true (say 1),
if true (say 2) (say 3),

-- If executes second block when condition is false
if false (say 4) (say 5),

-- If returns nil when without else block
say (if false (say 6)),

-- If returns block execution value
say (if true (7)),
say (if false (say 100, 8) (say 200, 9)),