The boolean operator 'If and only if' do not have a relation with the program instruction 'if'.

The programatic 'if' is a jump, not a boolean operator. It do not have truth table.

In logic:, if and iff can be seen like functions taking two booleans and returning a boolean

• 'if a then b' (noted a -> b): return true if a is false or b is true. Example: 'if I eat pizza then I fart' This is true even if I fart all the time (if b is true, we do not care about the value of a) as long as I fart when eating pizza (if a is true, b must be also true)
• 'a <-> b' is equivalent to 'a -> b and b -> a': the two should be true at the same time. I can only fart will eating pizza and cannot fart otherwise.