Basic broadcasting and receiving

Broadcasting and receiving is conceptually one of the most challenging ideas we've gotten to so far. That's because the idea is slightly more abstract than some of the other things we've discussed. Let's first talk a little about the principle it is built on, and then go into how it works in Scratch.

Getting ready

We have two separate ideas to think about. The first is the idea of broadcasting. Think of it as a radio station that sends out a signal that only radios can hear. If you are walking around outside, you're not going to hear anything. If you turn on a radio though, you can hear everything being broadcast. Receiving is kind of like the radio. It listens for a specific signal being broadcast, and then will trigger the code placed under it.

In Scratch, we have two blocks that act in this way. The broadcast block and the when I receive block, both of which are Events blocks. We'll talk more about these in the How it works… section coming up.

For this recipe...