When is the RTCPeerConnection.onicecandidate event fired?

Question

WebRTC

When does the RTCPeerConnection.onicecandidate event occur? In those examples that I found, there is always a check:

yourConnection.onicecandidate = function (event) {
    if (event.candidate) {
      send({
        type: "candidate",
        candidate: event.candidate
      });
    }
  };

What is the if (event.candidate) check for here? Indeed, in theory, onicecandidate should be called when a candidate is generated, why then check whether it exists or not every time?

Answer 1

The point is that when it gets all the candidates, the last one will come with null value. It makes no sense to pass empty data to another user, so a condition is set.