WEBVTT

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So teachers can be quite dangerous.

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So you do need to use them properly and really think about what you're doing.

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Every every single time when you use one and the reasons why using one.

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So you saw before that if you had a pointer but say this pointer and you set it to null pointer you

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can't dereferences right

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because it doesn't know it doesn't know what my pointer is at this point because no no pointer is not

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a type.

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This is not it it's not types doing something.

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This is very bad.

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OK.

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So that's kind of one pitfall.

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There are others though.

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So let's see a different example so say we want to return a pointer so like this in which we just kind

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of make it right here.

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So we say it's just five

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or turn the value of x and in let's just say it's pointer equals to phunk

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and we're going to do that's value pointed to by X..

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Winter is next winter.

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You got.

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And if try this.

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So what's happening here.

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Values one that's kind of strange.

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So remember what I said about lifetime here.

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So X will be destroyed at the end of the function.

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So if you remember the lifetime lecture this only has a lifetime of this function so it's destroyed

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as soon as it returns.

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So therefore returning an address that has been destroyed doesn't shouldn't exist anymore.

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At the end of this function.

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So the moral of the story here is you should never return an address of a local variable out of its

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function.

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Of course it's the same if you use a reference.

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So in a similar way you shouldn't do something like this.

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We had a pointer here.

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It's

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changes to be it's X so what changes FOID

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and you should do something like this.

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Say it.

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Why.

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Ten inch x 2 that can do this and it's set.

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Ch ch x 5 year an x K.

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You X is.

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So this

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so the value of x is 5 even though we supposedly changed it right.

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Well this is it is not quite the same.

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This doesn't do what you think it does.

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K because this pointer will be destroyed by the end of this function.

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Similar to the last example.

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So you're kind of giving it a an address that will be destroyed and itself will be destroyed at the

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end of the function.

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So it doesn't really change X at all here.

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So we're seeing some more pitfalls that we might run into a bit later when we get into some more more

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new stuff.