关系表类型，这是一个很强大的类型。我们可以把这个类型看作是一个数组。只是C语言的数组，只能用正整数来作索引；在Lua中，你可以用任意类型的值来作数组的索引，但这个值不能是nil。同样，在C语言中，数组的内容只允许一种类型；在Lua中，你也可以用任意类型的值来作数组的内容，nil也可以。基本介绍注意三点： 第一，所有元素之间，总是用逗号”，”隔开； 第二，所有索引值都需要用”[“和”]”括起来；如果是字符串，还可以去掉引号和中括号；即如果没有[]括起，则认为是字符串索引 第三，如果不写索引，则索引就会被认为是数字，并按顺序自动从1往后编；例如：tt={“hello”,33}value=4tab={[tt]=”table”,key=value,[“flag”]=nil,11}print(tab[tt])print(tab.key)print(tab[1])以上写法都是对的。http://hovertree.com/hovertreescj/look = {[www] = “ok”}这样是不对的，www没有赋值，所以默认为nil因此出错table index is nil—temp = 1tab = {[temp] = 1, 11}print(tab[temp]) –此时的结果是11，因为11没有显式对应的key，因此从1开始，如果前面定义了，则覆盖其value—temp = 2tab = {[temp] = 1, 11}temp = 1print(tab[temp]) — 结果是11，虽然定义时[temp] = 1,但是后来我们改变了temp的值，所以指向另外的key了以上可知：1.对于字符串，在｛｝定义时，可以key = value, 也可以[“flag”] = nil，索引都是string类型，对于非nil类型变量（包括字符串），都可以[variable]=value的方式2.使用table时，对于字符串，可以通过.的方式访问，也可以通过[]方式访问。tab[a]，tab[b]，只要a==b那么tab[a]可以访问到tab[b]的值3.不管定义索引时用的是常量还是变量，最终table中value的索引key是常量，不会随变量的改变而变化该value的key嵌套tb11={tb12={bool=true}}– simple, it’s a table IN a table :)– Call magic!print(tb11.tb12.bool)– works fine, since it’s calling the key and value correctly.print(tab11[“tb12”].bool)–same as line 33print(tab11.tb12[“bool”])–same as line 33print(tab11[“tb12”][“bool”])–same as line 33修改table的value–Altering a table’s content. Basically manipulating the values of the keys.lucky={john=”chips”,jane=”lemonade”,jolene=”egg salad”}lucky.jolene=”fruit salad”–changed the value to “fruit salad” instead of “egg salad”lucky.jerry=”fagaso food”– adding a new key-value pair to the container lucky.lucky.john=nil– remove john from giving anything or from being a key.table的易变性a={};b=a;print(a==b)–> truec,d={},{};print(c==d)–>falsetable库函数使用———————————————————–1. table.sort (table [, comp])Sorts table elements in a given order,in-place, fromtable[1]totable[n], wherenis the length of the table. Ifcompis given, then it must be a function that receives two table elements, and returns true when the first is less than the second (so thatnot comp(a[i+1],a[i])will be true after the sort). Ifcompis not given, then the standard Lua operator<is used instead.
The sort algorithm is not stable; that is, elements considered equal by the given order may have their relative positions changed by the sort.
name={“you”,”me”,”him”,”bill”}–table.sort – only works with arrays!table.sort(name)fork,vinipairs(name)doprint(k,v)end–table.sort uses callbacks. a function that is writtent to be called by a library function.functioncmp(a,b)ifstring.sub(a,2,2)<string.sub(b,2,2)thenreturntrueelsereturnfalseendendtable.sort(name,cmp)fork,vinipairs(name)doprint(k,v)end2. table.insert (table, [pos,] value)Inserts elementvalueat positionposintable, shifting up other elements to open space, if necessary. The default value forposisn+1, wherenis the length of the table so that a calltable.insert(t,x)insertsxat the end of tablet.–table.insert –an easy to copy a table to another table or adding elements to an array.!foo={“a”,”c”,”d”}bar={}functionprintt(table)fori=1,#tabledoprint(i,table[i])endendprint(“before insert:”)printt(foo)table.insert(foo,2,”b”)print(“after insert”)printt(foo)3. table.concat (table [, sep [, i [, j]]])Given an array where all elements are strings or numbers, returnstable[i]..sep..table[i+1] ··· sep..table[j]. The default value forsepis the empty string, the default foriis 1, and the default forjis the length of the table. Ifiis greater thanj, returns the empty string.–table.concat does what it implies. Takes an array and concates to one string.num={1,2,3,4,5,6}print(table.concat(num,”<“))4. table.remove (table [, pos])
Removes fromtablethe element at positionpos, shifting down other elements to close the space, if necessary. Returns the value of the removed element. The default value forposisn, wherenis the length of the table, so that a calltable.remove(t)removes the last element of tablet.
abc={“a”,”b”,”c”}print(table.remove(abc,2))print(“abc length = “..#abc)5. table.maxn (table)
Returns the largest positive numerical index of the given table, or zero if the table has no positive numerical indices. (To do its job this function does a linear traversal of the whole table.)
–table.maxnapple={“a”,”p”,[5]=”e”}print(table.maxn(apple))– 5duck={[-2]=3,[-1]=0}print(table.maxn(duck))– 0面向对象编程–note for a object to work, it needs a closure(inner function with an upvalue(a local value from a higher scope))–note: the more closures made, the slower the program would run.functionmg1(n)localfunctionget()returnn;endlocalfunctioninc(m)n=n+m;endreturn{get=get,inc=inc}endobject=mg1(50)print(object.get())print(object[“get”]())object.inc(2)print(object.get())—————————————-dolocalfunctionget(o)returno.oneendlocalfunctioninc(self,two)self.one=self.one+twoendfunctionmg3(one)return{one=one,get=get,inc=inc}endenda=mg3(50)a:get()a.inc(a,2)print(a:get())—————————————-dolocalT={};functionT:get()returnself.n;endfunctionT:inc(m)self.n=self.n+m;endfunctionmg4(n)return{n=n,get=T.get,inc=T.inc}endendc=mg4(30)print(c:get())c:inc(4)print(c:get())推荐：http://www.cnblogs.com/roucheng/p/lua1.html真正的强者，不是流泪的人，而是含泪奔跑的人。
