Difference between revisions of "Talk:Arrays (Papyrus)"

Programmers have to be even more obsessive because computes are dumb and need every little detail written down.

Programmers have to be even more obsessive because computes are dumb and need every little detail written down.

First the computer needs to know what kind of things will be in the list, that it will be a list, the name of the list.

First the computer needs to know what kind of things will be in the list, that it will be a list, the name of the list.

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But many times we need to also tell the computer to make enough storage space to hold the number of items we plan to store.

But many times we need to also tell the computer to make enough storage space to hold the number of items we plan to store.

FoodItem[] GroceryList = new Fooditem[4]

FoodItem[] GroceryList = new Fooditem[4]

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Then the items are stored in the numbered locations, but it's easier for the computer to start counting at zero instead of one, and has to be reminded of which list every single time.

Then the items are stored in the numbered locations, but it's easier for the computer to start counting at zero instead of one, and has to be reminded of which list every single time.

GroceryList[3] = "Bananas"

GroceryList[3] = "Bananas"

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Finding out how many items are in the list is easy. (Actually it's how many slots are available, even if some are blank.)

Finding out how many items are in the list is easy. (Actually it's how many slots are available, even if some are blank.)

GroceryList.length

GroceryList.length

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Getting the values back isn't bad as long as you remember that the computer starts counting at zero.

Getting the values back isn't bad as long as you remember that the computer starts counting at zero.

FoodItem TheThirdItem = GroceryList[2]

FoodItem TheThirdItem = GroceryList[2]

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When you need to tell the computer to expect a list, you put the square brackets after the name of the type of items the list will hold.

When you need to tell the computer to expect a list, you put the square brackets after the name of the type of items the list will hold.

Function BuyThese(FoodItem[] ShoppingListForToday)

Function BuyThese(FoodItem[] ShoppingListForToday)

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But to do something with an entire list you would just use it's name.

But to do something with an entire list you would just use it's name.

BuyThese(GroceryList)

BuyThese(GroceryList)

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The real power of lists only appears when you need to do the same thing with every item in the list. We can loop through all of the items in the list by their index position.

The real power of lists only appears when you need to do the same thing with every item in the list. We can loop through all of the items in the list by their index position.

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But passing that list into the BuyThese function really is like handing someone a list. If code inside that function changes or removes some of the items, then they are changed everywhere that list is referenced. We aren't making copies of the list, just letting different parts of the code see it (and some may call it different things, but it's the same list).

But passing that list into the BuyThese function really is like handing someone a list. If code inside that function changes or removes some of the items, then they are changed everywhere that list is referenced. We aren't making copies of the list, just letting different parts of the code see it (and some may call it different things, but it's the same list).

So after we've called "BuyThese(GroceryList)" we'll be able to see if anything wasn't available.

So after we've called "BuyThese(GroceryList)" we'll be able to see if anything wasn't available.

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