Display contents of tables in lua
If you have static predefined field names in your data records, this simpler version may work for you:
for i,t in ipairs(people) do
print('Record',i)
print('Name',t.name)
print('Address',t.address)
print('Phone',t.phone)
print()
end
To display nested tables you will have to use nested loops.
Also, use ipairs
to iterate through array-like tables, and pairs
to iterate through record-like tables.
local people = {
{
name = "Fred",
address = "16 Long Street",
phone = "123456"
},
{
name = "Wilma",
address = "16 Long Street",
phone = "123456"
},
{
name = "Barney",
address = "17 Long Street",
phone = "123457"
}
}
for index, data in ipairs(people) do
print(index)
for key, value in pairs(data) do
print('\t', key, value)
end
end
Output:
1
phone 123456
name Fred
address 16 Long Street
2
phone 123456
name Wilma
address 16 Long Street
3
phone 123457
name Barney
address 17 Long Street
This recursively serializes a table. A variant of this code may be used to generate JSON from a table.
function tprint (tbl, indent)
if not indent then indent = 0 end
local toprint = string.rep(" ", indent) .. "{\r\n"
indent = indent + 2
for k, v in pairs(tbl) do
toprint = toprint .. string.rep(" ", indent)
if (type(k) == "number") then
toprint = toprint .. "[" .. k .. "] = "
elseif (type(k) == "string") then
toprint = toprint .. k .. "= "
end
if (type(v) == "number") then
toprint = toprint .. v .. ",\r\n"
elseif (type(v) == "string") then
toprint = toprint .. "\"" .. v .. "\",\r\n"
elseif (type(v) == "table") then
toprint = toprint .. tprint(v, indent + 2) .. ",\r\n"
else
toprint = toprint .. "\"" .. tostring(v) .. "\",\r\n"
end
end
toprint = toprint .. string.rep(" ", indent-2) .. "}"
return toprint
end
running your table through this:
local people = {
{
name = "Fred",
address = "16 Long Street",
phone = "123456"
},
{
name = "Wilma",
address = "16 Long Street",
phone = "123456"
},
{
name = "Barney",
address = "17 Long Street",
phone = "123457"
}
}
print (tprint(people))
generates this:
{
[1] = {
name= "Fred",
phone= "123456",
address= "16 Long Street",
},
[2] = {
name= "Wilma",
phone= "123456",
address= "16 Long Street",
},
[3] = {
name= "Barney",
phone= "123457",
address= "17 Long Street",
},
}