JavaScript中不能作為變量名的關鍵字和保留字總結：
1、js中的關鍵字：
| break | case | catch | continue | default |
| delete | do | else | finally | for |
| function | if | in | instanceof | new |
| return | switch | this | throw | try |
| typeof | var | void | while | with |
2、js中的保留字：
| abstract | boolean | byte | char | class |
| const | debugger | double | enum | export |
| extends | final | float | goto | implements |
| import | int | interface | long | native |
| package | private | protected | public | short |
| static | super | synchronized | throws | transient |
| volatile |
上面這些字符在js里面都不可作為變量名，作為變量名時js可能會報錯或者不執行。