Can anyone verify whether the following is a travelling violation? Offensive player with the ball comes to a two-footed jump stop upon catching a pass. The offensive player jumps to attempt a shot. While offensive player is in the air, defensive players slaps the ball downward out of offensive players hands. Before landing and before the ball touches the ground, the offensive player regains possession of the ball and lands. Is this travelling?

If the ball clearly was knocked out of or left the shooters hand, it is NOT a travel. If he maintains contact/control, then travel or jumpball is defender is touching it also.

If A1 goes up, B1 hits ball, A1 does not lose contact with the ball, does B1 have to remain in contact with the ball for it to be a jumpball (heldball)? I am confused by the response that this could be a travel if A1 remains in contact. I thought with defender interrupting shot while the ball is in the shooter's hands, it is a jumpball if it never leaves the would-be shooter's hands, a blocked shot if it does.

If the defender prevents the release of the ball, held ball (NFHS Rule 4, Section 25, Article 2). There is also a casebook play 4.25.2.

In the original post, it is clearly stated that the ball was knocked loose by the slap by B1. Although the ball never hit the floor, control by A1 ended (holding or dribbling a live ball inbounds), therefore, no travel. Control, not contact, determines the call. For instance, if B1 contacted the ball but didn't knock it loose and didn't prevent it from being released, and A1 returned to the floor, travel is the call. IMHO, if B1 knocked it loose and A1 juggled the ball while trying to get it back, without the ball hitting the floor, and even took a couple of steps while juggling, you have nothing because original control had ended. If he/she is not holding or dribbling a live ball inbounds, he/she does not have control.