Jumps only if the last evaluated if-block (see 00d6) returned false.
if 0 is_defined $hPlayer jf @NoPlayer get_player_car $hPlayer, $hCar @NoPlayer
Working with 'jump if false' instead of 'jump if true' may seem weird at first, but it actually allows for easier writing of conditional code. With jt, the code for if [conditions] then [statements] becomes:
if [conditions] jt @DoStatements jump @SkipStatements @DoStatements [statements] @SkipStatementsWhereas with jf, it becomes:
if [conditions] jf @SkipStatements [statements] @SkipStatements
See 0002 for label commentary.