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I hope you enjoyed this assignment and the two questions associated with it, and that you were able

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to complete both questions without any problem.

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In this video, we are going to go over the solution to both questions and the assignment.

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The first question is create a function that takes one argument called Val that is of type vector with

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the values one, three, five and seven.

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So we will create our function and we will call it Czech Val and it is going to be up type vector.

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So we know that and it has values one, three, five and seven.

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So it is a type I eight.

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And then inside of this function, check the first value of the vector and see if it is equal to one.

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At the value is equal to one, then return true, otherwise return false.

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So we know that we're going to need to return a boolean.

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And so now we want to check if Val of zero is equal to one.

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If it is return true else return false.

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So now up here we are going to create our vic and we can use the VEC macro for this and we are going

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to have one, three, five and seven.

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So now we want to print out if our value

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is true or not.

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So we are going to call check Val and we will say on vector and then add the value 15 to the vector

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so we can do push 15 and then to confirm our results, we want to print out the vector.

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So will this code compile or not?

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It does not compile because vector does not implement the copy trait because it is not a simple type.

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So in order for us to pass the vector into this function and then still be able to use it after this

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function call, we need to pass it in by reference.

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That way the function down here called Check.

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Val does not take ownership of our vector which we created here.

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So now if we go to run this, it will not execute fine.

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Because I forgot the mute keyword.

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Since we are pushing a value in, we have to make it a mutable variable.

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And now if we run it, it will execute perfectly fine.

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And this is a good segway in the question too.

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So create a function called add two.

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And this function is going to take one parameter that is of IE eight and we're going to add two to it.

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So we'll say Val plus two.

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And in this case, we don't care about returning our value.

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So up here we want to say let mute value equal to two and now we want to call add two on value.

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And what I want to do here is now I want to say value is equal to five.

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So will this compile since we are not passing in value by reference.

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So let's see what we get.

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So we have a need to not return a value so we get no errors when we try to re access value here.

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And the reason to that and this is going to answer the question of do you have to pass the value by

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reference in order for you to maintain ownership of it inside of main?

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And the answer to that question is no, you do not have to pass the value by reference.

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There is a caveat for that because you do not have to pass simple types that implement the copy trait.

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And we will talk more about the copy trait later on in this course.

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But for now, I want to open up this concept to you that certain values are considered simple, so integers

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are simple.

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I ate I 32, i 64 and so on.

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And it's simple because it is easy to copy those values.

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So when you pass in this case an I eight into a function, you do not and I repeat, you do not have

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to pass it by reference in this case because it implements the copy trait.

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So that is just something that I wanted to introduce to you now, and it's going to be something that

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we cover on later on in this course.