Question

我要做的是使用Lua中的以下代码显示表的内容。

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 k, v in pairs(people ) do
    print(k, v)
end

我得到的输出是：

1   table: 0x9a2d8b0
2   table: 0x9a2d110
3   table: 0x9a2cb28

Answer 1

要显示嵌套表，您必须使用嵌套循环。

另外，使用ipairs遍历数组表，并pairs遍历记录表。

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

输出：

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

Answer 2

这递归地序列化一个表。此代码的变体可用于从表中生成JSON。

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

通过以下方式运行你的表：

 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))

生成这个：

  {
  [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",
    },
}

Answer 3

如果您的数据记录中有静态预定义字段名称，这个更简单的版本可能适合您：

let pdf = new pdfkit();

let buffers = [];
pdf.on('data', buffers.push.bind(buffers));
pdf.on('end', () => {

    let pdfData = Buffer.concat(buffers);

    // ... now send pdfData as attachment ...

});

pdf.text('Hello', 100, 100);
pdf.end();

Answer 4

我不确定您要使用哪种IDE。但是由于任何原因，无论您是谁还是其他任何发现此线程的人都在Visual Studio Code中工作，Lua Debug extension将在为您构建的自定义表显示所有关联数组值方面做得很好。

我真正喜欢的是，不仅可以显示初始值，而且如果以后决定更改值，则可以使用此扩展名进行操作，并通过“调试控制台”查看所做的调整。标签。

我以您的确切示例为例，只需在调试中键入人员，然后显示所有值即可。

Answer 5

解决方案1：py.repr https://github.com/waketzheng/luapy

$ wget https://raw.githubusercontent.com/waketzheng/luapy/main/python.lua

py=require('python')
> tab = { 1, 2, 3 }
> py.repr(tab)
[
    1,
    2,
    3
]
> tab = { a=1, b=2, c=3 }
> py.repr(tab)
{
    "c": 3,
    "a": 1,
    "b": 2
}
> tab = { a='a', b='b', c='c', d='d', e='e', f='f', g='g' }
> py.repr(tab)
{
    "g": "g",
    "a": "a",
    "b": "b",
    "c": "c",
    "d": "d",
    ...
}

解决方案2：lu.prettystr https://luaunit.readthedocs.io/en/latest/#pretty-printing

$ wget https://raw.githubusercontent.com/bluebird75/luaunit/main/luaunit.lua

> lu = require('luaunit')
> t1 = {1,2,3}
> t1['toto'] = 'titi'
> t1.f = function () end
> t1.fa = (1 == 0)
> t1.tr = (1 == 1)
> print( lu.prettystr(t1) )
{1, 2, 3, f=function: 00635d68, fa=false, toto="titi", tr=true}

Answer 6

假设您的数据结构是JSON可序列化的（如上述示例），您可以作弊并使用rxi/json.lua（MIT许可证）来帮助漂亮地打印对象。只需将json.lua放到您的项目中，即可使用：

json = require "json"
for k, v in pairs(people) do
    print(k, json.encode(v))
end

1       {"address":"16 Long Street","name":"Fred","phone":"123456"}
2       {"address":"16 Long Street","name":"Wilma","phone":"123456"}
3       {"address":"17 Long Street","name":"Barney","phone":"123457"}

在lua中显示表的内容

6 个答案: