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In the last lesson, we looked at functions that return some sort of value.

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We created a function called format_name that returned a string. In this

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lesson

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let's see what happens when a function has more than one return statement.

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When the computer encounters a line that has the word return on it,

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then it knows that this line is the end of the function.

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If I add a line of code after the return keyword, notice what happens when I run

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this code. It doesn't ever get executed.

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And this has because the return tells the computer that this is the end of the

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function and you should now exit the function.

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You can actually have multiple return keywords within the same function,

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and you can even have a empty return keyword.

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So just the return keyword without anything afterwards.

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So for example,

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we could check whether if the fname is equal to an empty string or the lname

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is equal to an empty string. So this case,

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it means that when we called it format name, maybe we didn't give it any inputs.

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For example, let's say that instead of just calling the function as it is,

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we actually used the input function.

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So what is your first name and what is your last name?

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Now

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what happens is it'll ask us for a input and it will take these two inputs

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and then call that function and return the formatted version to be printed.

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So now in this case, it's possible that we might have just not given it

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a first name or not given it a last name and it probably shouldn't go through

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these lines of code. But at the moment, it's still running this function

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trying to get the title case from the empty string and then printing it.

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And I can prove this to you by just adding an extra word in here.

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So again, empty first name, empty, last name,

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and then it's print result and then of course nothing.

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How can we get it to bypass the rest of the code if the user typed in an empty

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first name or last name? Well,

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we could use what I mentioned before, an early return.

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So we could just write return without anything afterwards

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and this is going to escape the function.

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So it's basically going to terminate the function early.

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Now this time, if I leave an empty first name and last name,

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you'll see it prints none because there is no output from this to print.

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Now, of course,

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it's probably safer to actually return something that tells the developer what's

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actually going on so we can give a meaningful message,

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like return, something like this.

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So this way we can catch the cases when something is not quite right and then

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exit our function instead of wasting time for it to continue working on

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something that we don't want it to do.

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We've covered a number of things in today's lesson

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and I want you to combine this with your existing knowledge to tackle the

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challenge in the next lesson

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to get to grips with this concept of functions with inputs and with outputs.