In the third Hondajet marketing video there is a sword-like object visible on the nose of the aircraft.
What is this used for?
It is a Pitot tube.
It is used to measure some air data values, depending on the model.
The most basic will measure only pressures (and then "derives" the velocity of the aircraft), the most advanced will measure angle of attack and sideslip as well.
The one in the photo is particularly long to make sure that is measuring values in the undisturbed airflow in front of the aircraft. It is a model usually seen in flight tests or on fighter aircraft.
In flight tests, because despite the accurate CFD modelling available today, uncertainties are still present during the first flights (that's why they are tests). The long probe gives a reference as much undisturbed as possible.
During normal operations you will generally find smaller probes, such as the ones found in this other question.
Fighter aircraft need the long boom for the reasons seen in this question.