第一种遍历方式:
for key, value in ipairs(table) do end
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注:这种方式的遍历只会从key为1的地方开始,一直以key递增1的顺序来遍历,若找到一个递增不是1的key就结束遍历,无论后面是否仍然是顺序的key。请看下面例子:
Sample_1:
local tab1 = { [1] = 1, [2] = 2, [3] = 3, [4] = 4, } for key, value in ipairs(tab1) do print(value) -->1 2 3 4 end
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Sample_2:
local tab2 = { [1] = 1, [2] = 2, [3] = 3, [5] = 5, [6] = 6, } for key, value in ipairs(tab2) do print(value) -->1 2 3 end
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Sample_3:
local tab3 = { [2] = 2, [3] = 3, [4] = 4, } for key, value in ipairs(tab3) do print(value) -->没有打印 end
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第二种遍历方式:
for key, value in pairs(table) do end
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注:这种方式的遍历是根据table中key的hash值排列的顺序来遍历,并非是table中key的排列顺序,并且不关心key是否从1开始和key是否以1递增。请看下面例子:
Sample_1:
local tab1 = { [1] = 1, [2] = 2, [3] = 3, [4] = 4, } for key, value in pairs(tab1) do print(value) -->1 2 4 3 end
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Sample_2:
local tab2 = { [1] = 1, [2] = 2, [3] = 3, [5] = 5, [6] = 6, } for key, value in pairs(tab2) do print(value) -->1 2 3 end
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Sample_3:
local tab3 = { [2] = 2, [3] = 3, [4] = 4, } for key, value in pairs(tab3) do print(value) -->3 2 4 end
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第三种遍历方式:
注:这种方式的遍历关键的地方在于获取table的大小,#(table)只会从key为1的地方开始,一直以key递增1的顺序来遍历,若找到一个递增不是1的key就结束遍历并且返回table的大小,无论后面是否仍然是顺序的key。请看下面例子:
Sample_1:
local tab1 = { [1] = 1, [2] = 2, [3] = 3, [4] = 4, } print("#table:"..#(tab1)) -->4 for i = 1, #(tab1) do print(tab1[i]) -->1 2 3 4 end
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Sample_2:
local tab2 = { [1] = 1, [2] = 2, [3] = 3, [5] = 5, [6] = 6, } print("#table:"..#(tab2)) -->3 for i = 1, #(tab2) do print(tab2[i]) end
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Sample_3:
local tab3 = { [2] = 2, [3] = 3, [4] = 4, } print("#table:"..#(tab3)) -->0 for i = 1, #(tab3) do print(tab3[i]) -->没有打印 end
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第四种遍历方式:
for i=1, table.maxn(table) do end
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注:这种方式的遍历和第三种方式差不多,关键的地方是在table.maxn(table),table.maxn(table)的意思是获取table中最大值的key。在lua5.2版本table.maxn被移除,请看下面例子:
Sample_1:
local tab1 = { [1] = 1, [2] = 2, [3] = 3, [4] = 4, } print("table.maxn:"..table.maxn(tab1)) -->4 for i = 1, table.maxn(tab1) do print(tab1[i]) -->1 2 3 4 end
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Sample_2:
local tab2 = { [1] = 1, [2] = 2, [3] = 3, ["a"] = 4, [5] = 5, [6] = 6, } print("table.maxn:"..table.maxn(tab2)) -->6 for i = 1, table.maxn(tab2) do print(tab2[i]) -->1 2 3 nil 5 6 end
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Sample_3:
local tab3 = { [2] = 2, [3] = 3, [4] = 4, } print("table.maxn:"..table.maxn(tab3)) -->4 for i = 1, table.maxn(tab2) do print(tab3[i]) -->nil 2 3 4 nil nil end
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