函数调用由一个任意的主题表达式，后跟要给开口的圆括号，逗号分隔表达式作为参数，以闭口的圆括号结束。 > Functions calls consist of an arbitrary subject expression followed by an opening parenthesis (, a comma , separated list of expressions as arguments and a closing parenthesis ). ~~~ subject(); // call with no arguments subject(e1); // call with one argument subject(e1, e2); // call with two arguments // call with multiple arguments subject(e1, ..., eN); ~~~