1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
counter = {
count = 0
}
function counter.get(self)
return self.count
end
function counter:inc()
self.count=self.count+1
end
print(counter.get(counter))
counter.inc(counter)
print(counter.get(counter))
counter2={
count=4,
get = counter.get,
inc = counter.inc,
}
print(counter2:get())
counter.inc(counter2)
print(counter2.get(counter2))
print()
tb1 ={ "alpha" , "beta" , "gamma" }
mt={}
setmetatable(tb1,mt)
print(getmetatable(tb1) == mt)
print()
function mt.__add(a,b)
local result = setmetatable({},mt)
for i=1,#a do
table.insert(result,a[i])
end
for i=1,#b do
table.insert(result,b[i])
end
return result
end
tb2={ "aaa" , "bbb" , "ccc" }
res=tb1+tb2
for i,v in ipairs(res) do
print(v)
end
print()
function mt.__unm(a)
local result = setmetatable({},mt)
for i=#a , 1 ,-1 do
table.insert(result,a[i])
end
return result
end
res=-tb1+tb2
for i,v in ipairs(res) do
print(v)
end
print()
function mt.__tostring(a)
local result = "{"
for i,v in ipairs(a) do
result = result.. " " ..v
end
result = result.. " } "
return result
end
print(tb1)
function mt.__index(tb1,key)
print( "there is no " ..key.. " in the table" )
return nil
end
print(tb1[ "fsy" ])
function mt.__newindex(a,key,v)
if ( key == "haha" ) then
error( " Stop laugh!" ,2)
else
rawset(a,key,v)
end
end
tb1.haha= "heihei"
|
运行结果:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
|
0
1
4
5
true
alpha
beta
gamma
aaa
bbb
ccc
gamma
beta
alpha
aaa
bbb
ccc
{ alpha beta gamma }
there is no fsy in the table
nil
lua: my_test.lua:166: Stop laugh!
stack traceback:
[C]: in function 'error'
my_test.lua:160: in function <my_test.lua:158>
my_test.lua:166: in main chunk
[C]: ?
|