Initial data commit

Task/Empty-string/Lua/empty-string.lua

@@ -0,0 +1,25 @@
+-- create an empty string 3 different ways
+str = ""
+str = ''
+str = [[]]
+
+-- test for empty string
+if str == "" then
+  print "The string is empty"
+end
+
+-- test for nonempty string
+if str ~= "" then
+  print "The string is not empty"
+end
+
+-- several different ways to check the string's length
+if string.len(str) == 0 then
+  print "The library function says the string is empty."
+end
+if str:len() == 0 then
+  print "The method call says the string is empty."
+end
+if #str == 0 then
+  print "The unary operator says the string is empty."
+end