Peter Michaux讨论一对重要的Parens 。

Peter Michaux discusses the difference in An Important Pair of Parens.

基本上，括号是一个约定，表示紧接着调用的函数表达式，而不是普通函数。特别是如果函数体很长，这会减少意外，

Basically the parentheses are a convention to denote that an immediately invoked function expression is following, not a plain function. Especially if the function body is lengthy, this reduces surprises,