How do you find the position of a certain value in a table?
I've been searching and searching and it's only led me to what's probably the completely wrong answer. All that I've came up with in my search would be something like this..
--This code throws an error because it probably doesn't make any sense
x = {"first", "second", "thrid"}
print(string.find(table.concat(x, "third")))
--print(string.find(table.co:2: bad argument #2 to 'find' (string expected, got no value)
What I'm trying to print with the above code is "3", with the logic that "third" is the third value in the table.
2 answers
Your trying to find the key from a value, but this isn't how tables work. The key is used to find the value, not the other way around.
However we can accomplish what I believe you want pretty easily with a dictionary. All we need to do is make the key be the string, and make the value be the number. This means we can take a string and find what number its value is.
local x = {
first = 1,
second = 2,
third = 3
}
print(x.second) -->2
Or, equivalently;
local x = {
["first"] = 1,
["second"] = 2,
["third"] = 3
}
print(x["second"]) -->2
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Check line 3. The error tells you that string.find needs a second argument. You put "third" in the wrong place.
x = {"first", "second", "third"}
print(string.find(table.concat(x, ", "), "third"))
I would break up that line a bit so I could read the script clearly.
x = {"first", "second", "third"}
concat = table.concat(x)
find = string.find(concat, "third")
print(find)
However, I'm assuming that this won't give you what you want. "first" is 5 characters long, "second" is 6, and "third" is 5. What you want is the position of "third" in the table. So, let's try a different approach. We'll use a generic for loop.
x = {"first", "second", "third"}
for i, v in pairs(x) do --Look through "x"
if i == 3 then --If we're on the third index
print(v) --Print the third index
end
end
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