字符串函数:
数学函数:
= 123.123456 ();
(,3);
(1,10);
数组函数:
= (, "Maroon 5");
(, "Bruno Mars" (, "Nickelback" (, "Katy Perry" (, "Macklemore" (
= ("david","alana","violet","rory" ();
(", ", );
();