ch05 exercises

exercises/ch05/ex5_8.lua

@@ -0,0 +1,31 @@
+local function concat(strs)
+    local res = ""
+    for i = 1, #strs do
+        res = res .. strs[i]
+    end
+
+    return res
+end
+
+local function random_str()
+    return tostring(math.random(100000, 999999))
+end
+
+local strs = {}
+for i = 1, 200000 do
+    strs[i] = random_str()
+end
+
+local time_start = os.clock()
+concat(strs)
+local own_concat_time = os.clock() - time_start
+
+print("Own concat time: " .. own_concat_time)
+
+time_start = os.clock()
+_ = table.concat(strs)
+local table_concat_time = os.clock() - time_start
+
+print("table.concat time: " .. table_concat_time)
+
+print(("table.concat was %f%s faster"):format(own_concat_time / table_concat_time * 100, "%"))