JS understanding the weird parts 4-41 ~ 4-42 ASI

4-41 syntax parsers

4-42 Automatic semicolon insertion

• 通常會在換行時，javascript engine 會自動加上分號
• (ECMA 中ASI 的定義)[http://www.ecma-international.org/ecma-262/7.0/index.html#sec-rules-of-automatic-semicolon-insertion]

function getPerson(){
  return
  {
    firstname:"Sam"
  }
}
console.log(getPerson()); //undefined
// after ASI
function getPerson(){
  return ;
  {
    firstname:"Sam"
  };
}