面试lua笔试题各种坑

替换字符串"abcdefgh" 中的"abc"为"ddc"

local str ="abcdefgh";

b = string.gsub(str, "%abc", "ddc");

str = b;

print(str);

https://my.oschina.net/workhelu/blog/363949

pairs

1.pairs遍历table中的所有的key-vale 而ipairs会根据key的数值从1开始加1递增遍历对应的table[i]值

a = {[1] = "a1", [2] = "a2", [3] = "a3", [5] = "a4", [6] = "a5",}
for key, value in ipairs(a) do
  print(key, value)
end


结果：
1       a1
2       a2
3       a3

a = {[1] = "a1", [2] = "a2", [3] = "a3", [5] = "a4", [6] = "a5",}
for key, value in pairs(a) do
  print(key, value)
end
结果：
6       a5
2       a2
3       a3
1       a1
5       a4

function clone( object )

local lookup_table = {}

local function copyObj( object )

if type( object ) ~= "table" then

return object

elseif lookup_table[object] then

return lookup_table[object]

end

local new_table = {}

lookup_table[object] = new_table

for key, value in pairs( object ) do

new_table[copyObj( key )] = copyObj( value )

end

return setmetatable( new_table, getmetatable( object ) )

end

return copyObj( object )

end

local t1 = { "a","b","c"}

-- local t2 = clone(t1);

--t1[1] = "abc";

local t2 = t1;

t1[1] = "abc";

for i=1,#t2 do

print(t2[i]);

end