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‫So now we're going to create our insert function.

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‫And with insert, we're going to insert a new node with a particular value at a particular index.

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‫So let's bring up our linked list like this, and we're going to insert this node.

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‫And just as we've seen in the last couple of functions, we need to test to see if the index is out

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‫of bounds so we can't insert this at the index of negative one.

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‫Or we could say index less than zero.

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‫And also, we can't insert this at the index of five, or we could say index greater than the length.

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‫So we'll create an if statement here that says if the index is less than zero or the index is greater

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‫than the length return false.

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‫So the next situation is what if we insert this at the index of zero?

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‫If we put the node here, this is something we've already written code for.

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‫This is basically a pre append.

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‫So we'll say if the index is equal to zero, we will pretend that new node.

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‫But the other thing we also have to do here is return true.

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‫Similarly, if we're going to add the node here, we've written code for this as well.

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‫We'll say if the index is equal to the length, we'll run append.

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‫To append that new node.

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‫And also in this case, we will return.

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‫True.

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‫So now let's look at all three of these if statements.

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‫This if statement is if we have an index that's out of range, this is if the index is zero, we'll

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‫run pre append.

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‫And then if the index is equal to the length, we'll run append.

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‫So now let's bring back our linked list and look at how we would insert a node somewhere in the middle.

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‫Let's say we're going to insert this at the index of two.

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‫Like that.

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‫So let's put this back.

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‫What we're going to need is a variable to point to the node before the index where we're going to insert

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‫this.

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‫And the reason for that is we need to move this arrow down to the new node that's going to be temp next.

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‫If temp is on this side, we can't move that arrow.

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‫So let's put all of this back and we'll create the node and this variable.

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‫So we'll create our new node like this.

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‫So now we're going to create our temp variable.

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‫And remember, we want this to point to the node before the index where we're inserting the new node.

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‫So we'll set temp to be equal to get index minus one.

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‫So let's put this in with the rest of our code like this.

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‫And now let's bring back our linked list.

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‫So the first thing we're going to do is point next from the new node to that 23 node.

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‫So we'll do that by setting it equal to temp next.

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‫And when we do that, it'll point that up to the 23 node.

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‫We'll do that with this line of code.

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‫New node next equals temp next.

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‫And then we'll say temp next equals new node.

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‫And we'll do that with this line of code temp next equals new node.

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‫And that adds that into our linked list.

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‫So now let's look at this end with the rest of our code.

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‫And the only things left to do now are to increase the length by one.

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‫And then we need to return.

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‫True, because our return type is a boolean.

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‫So this is all of our code for insert.

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‫We'll look at this code in a moment and vs code.

53
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‫And when we do, we'll create this linked list with zero and two and then we'll run the insert function

54
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‫at the index of one with a value of one, and then our linked list will be 012.

55
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‫So now let's flip over to VS Code and take a look at this.

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‫So there is our insert function there and that I'm going to scroll up so we can take a look at this

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‫main function and this creates that linked list with zero and two and this will print that out and I'll

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‫run this.

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‫And you can see up here that our linked list has zero and two.

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‫So now I'm going to come up here.

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‫And I'll add this line where we insert a node with the value of one at the index of one.

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‫So now I'll run this and you can see that our linked list now has 012 and that is our function for insert.