Iterating through a table if it doesn't have an index?

[Lemony Lime]

So, I have a table something along these lines:

fruit = {
apples = { 'a', "red", 5 }
oranges = { 'o', "orange", 12 }
pears = { 'p', "green", 7 }
}

It doesn't seem like it's possible to access them based on their index, and the values themselves are tables, so I just made the first value of the nested table the index of it, so it now looks like this:

fruit = {
apples = { 0, 'a', "red", 5 }
oranges = { 1, 'o', "orange", 12 }
pears = { 2, 'p', "green", 7 }
}

So, now any time I use one of these tables, I know what the index is, but still can't get to the table using the index, so I started to write a function that loops through them all, and check the indexes until it finds the right one. Then I realized... how can I loop through them if I can't already refer to them by their index? So, now I'm stuck. I really want to be able to type fruit.apples vs fruit[1] most of the time, but of course it's necessary to do both at times.

[seanmd]

Code: Select all

for key,value in pairs(table) do
  ...
end

it is significantly slower than ipairs, but not worth worrying about.

also, if you want to get at one of those objects, you'd do

Code: Select all

fruit.apples

or to make it something you can access programmatically

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local fruitName = 'apples'
fruit[fruitName]

[T-Bone]

I don't really understand what your problem is. If you want numerical indexes, why don't you just use them? Alternatively, create an extra table like this:

Code: Select all

indexes = {"apples", "oranges", "pears"}

Now, when you want to use the string as index, you can still write

Code: Select all

fruits.apples

but when you want to use a numerical index you'll also be able to write

Code: Select all

fruits[ indexes[1] ]

[Wojak]

If I understand you correctly You want to access tables indexed by strings by using integers?
Well as long as apples will always be 0, oranges always 1 and pears always 2 you can use a helper table:

Code: Select all

fruit_id = {[0]='apples',[1]='oranges',[2]='pears'}

and access the table like this:

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somevar = fruit[fruit_id[0]] -- the same as somevar =  fruit.apples 
somevar = fruit[fruit_id[1]] -- the same as somevar =  fruit.oranges
somevar = fruit[fruit_id[2]] -- the same as somevar =  fruit.pears

also I would recommend not to use index = 0, as its something not natural in lua, so the example should be:

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fruit_id = {'apples','oranges','pears'}
somevar = fruit[fruit_id[1]] -- the same as somevar =  fruit.apples 
somevar = fruit[fruit_id[2]] -- the same as somevar =  fruit.oranges
somevar = fruit[fruit_id[3]] -- the same as somevar =  fruit.pears

witch also enables the numeric for iteration:

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for i=1, #fruit_id do
	somevar = fruit[fruit_id[i]]
end

witch is the same as:

Code: Select all

for i,v in pairs(fruit) do
	 somevar = v
end

[davisdude]

Also: indexes in Lua start at 1 usually, not 0.

In any case, if I think I understand you correctly, you want something like this:

Code: Select all

fruits = {
	apples = { first_letter =  'a', color = 'red', amount = 5 }, 
	oranges = { first_letter = 'o', color = 'orange', amount = 12 }, 
	pears = { first_letter = 'p', color = 'green', amount = 7 }, 
}
	
for i, fruit in pairs(fruits) do
	print(fruit.color)
end

Alternatively, you could also do this:

Code: Select all

fruits = {
	{ name = 'apples', 	first_letter = 'a', color = 'red',	  amount = 5  }, 
	{ name = 'oranges', first_letter = 'o', color = 'orange', amount = 12 }, 
	{ name = 'pears', 	first_letter = 'p', color = 'green',  amount = 7  }, 
}
	
for i, fruit in ipairs(fruits) do
	print(fruit.name..', '..fruit.first_letter..', '..fruit.color..', '..fruit.amount)
end