 So, one of the things that we have to identify is sort of how we want our functions to return values. You see, they can either return a value or they can return nothing. That's a very interesting thing, but if we sort of think about it, we've already kind of been looking at that a few different times. Say, for example, print. Print does not actually return anything. It displays something to the screen. I understand that sounds, you know, it's doing something. It's just not, you know, returning a value. That's why, again, we don't save it. But something like sum that added it functionally designed. Well, let's think about some more examples of this. We've learned about how to create a random number. That's another thing, random.random. This is going to give me some random number, but if I don't do anything with this, if I don't save this, this is, again, I'm going to return a value. If I don't save this somewhere, it just gets thrown out of memory. So it's just my way to sort of hold on to these different things. A way you can think about when to return. That's always, I always see students, they always have this kind of issue of, you know, when should I do these things? The way you can think about it is, you want to return when you want to ask a question. What is, for example, the price of this UPCI? Give me the results of a string that I want to search on Google. What time should I wake up tomorrow? Those are all return style kind of functions versus something a little bit nuts so much. These are more actions, things I want to happen. I want the volume to get lower. I want to change the channel. Notice I pass a parameter of what channel is there. I don't really care what channel I'm on or what channel I'm going to. I just want to change the channel. Same with volume. I don't care what the volume is. I just want it lower. It's too loud. Same again, I have an alarm. I don't care what my alarm is currently set to. It's clearly wrong. I need to set it to, you know, 8 AM. So let's say, for example, let's take that code that we did a little earlier in this class. We implemented the distance formula. So how can we do this? Well, the same kind of approach that we've had in the past. The first thing is I need to do my depth. And I'm going to go ahead and name it distance. Again, you should probably name these functions in things that they are, just like with a variable. Now in our case, our distance formula, if you notice we have an x2, x1, xy1, etc. So I have four parameters I need to be dealing with. So x1, y1, x2, y2. What are these values? I don't care. I don't know what they are. They're going to be something eventually, is, again, kind of the hallmark of the statement. So now all of a sudden I can do all of the same mathematical equations that I need to work off of in here. I'm going to jump to the top of my code and import math. You should always try and put your import statements at the very top. But now I can go, all right, well, I'm going to make the x portion. So x equals math.pow, x2 minus x1, I'm up to, I'm going to just copy and paste that. So I got y, y's instead of x's. This is where people start to get a little kind of hazy. So I've got my x, I've got my y, one, I don't recommend you name this next variable distance. That gets a little confusing because now what am I talking about? I'm talking about the function name or the variable name. In my case, I'm going to shorten it to dist, equals math.sqrt, x plus y, save. So now if we run it, all right, it got loaded into memory just like before. Distance, distance, 5, 5, 5, 0. In my theory, the distance should be 5 because of kind of the point at the 5, 5 and 5, 0, 5. So when I hit enter, I don't get that. Oh, well, it's because I didn't save it. Clearly, you didn't save it, so I don't know, save equals that. Saved, front saved. None. Now I'm not a betting man, but I know that that's not right. And the reason why is again, I didn't put my return statement in there just because I calculated this out. I don't have this. In fact, this doesn't exist. It was loaded into memory. This only exists inside of this distance function. So I have to, I have to, I have to return something if I want it to kind of happen outside my code. Now all of a sudden, I should see my 5. Now all of a sudden when I do saved, distance, 5, 5, 5, now all of a sudden I've got my 5.