在show_code函數中為什么要將函數shuffle()賦值給變量code呢，還有那個for循環是怎么回事，函數shuffle中的隨機數為什么還要減去0.5呢/*生成驗證碼*/ (function create_code(){ function shuffle(){ var arr=['1','r','Q','4','S','6','w','u','D','I','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p', 'q','2','s','t','8','v','7','x','y','z','A','B','C','9','E','F','G','H','0','J','K','L','M','N','O','P','3','R', '5','T','U','V','W','X','Y','Z']; return arr.sort(function(){ return (Math.random()-.5); }); }; shuffle(); function show_code(){ var ar1=''; var code=shuffle(); for(var i=0;i<6;i++){ ar1+=code[i]; }; $(".reg-box .phoKey").text(ar1); }; show_code(); $(".reg-box .phoKey").click(function(){ show_code(); }); })();