Lua: Adding multiple rows to tables

Question

Ok, so I'm looking to quickly generate a rather large table. Something that would look like this:

table{
{1, 1, 1, 1},
{1, 1, 1, 1},
{1, 1, 1, 1},
}

Only the table would contain far more rows, and far more values in those rows. I know using table.insert() I can easily add however many I need to a single row, but is there anyway I can also add whole new rows without typing it all out?

A not-quite-a-duplicate of stackoverflow.com/questions/13214926/… — Bartek Banachewicz
– Bartek Banachewicz, Commented Feb 26, 2013 at 9:33

Bartek Banachewicz · Accepted Answer · 2013-02-26 09:33:16Z

5

Use a for loop.

t = { }
for i = 1,100 do
    table.insert(t, i) -- insert numbers from 1 to 100 into t
end

2D arrays are also very simple

t = { }
for row = 1,20 do
    table.insert(t, { }) -- insert new row
    for column = 1,20 do
        table.insert(t[row], "your value here")
    end
end

You could remember current row as in local current_row = t[row], but don't try these things to improve performance until you profile! Use them merely for readability, if you think it clearer expresses the purpose.

Also note that (and it's especially funky in 5.1 and newer with the #) you can just directly assing values to nonexisting indices, and they will be added.

edited Feb 26, 2013 at 9:33

answered Feb 26, 2013 at 9:25

Bartek Banachewicz

39.5k8 gold badges100 silver badges141 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

lhf · Accepted Answer · 2013-02-26 10:59:31Z

4

You don't need to use table.insert:

t = {}
for row = 1,20 do
    t[row] = {}
    for column = 1,20 do
        t[row][column]= "your value here"
    end
end

answered Feb 26, 2013 at 10:59

lhf

72.8k11 gold badges117 silver badges162 bronze badges

3 Comments

Max Well Over a year ago

Is it possible to use named keys in this type of setup instead of numeric row/column indexing? How would I do that?

lhf Over a year ago

@MaxWell, yes, just adjust the loops accordingly. Please ask a separate question with examples of what you're trying to achieve.

Max Well Over a year ago

Thanks, @lhf. I finally worked out how to set it up. Now I'm struggling with how to sort it. Here's my original post on the issue. stackoverflow.com/questions/73587448/…

Collectives™ on Stack Overflow

Lua: Adding multiple rows to tables

2 Answers 2

Comments

3 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related