关键字
关键字不能作为标识符（变量名），有特殊功能。
| break | case | catch | class |
|---|---|---|---|
| const | continue | debugger | default |
| delete | do | else | extends |
| finally | for | function | if |
| import | in | instanceof | return |
| super | switch | this | throw |
| typeof | var | void | while |
| with | yield |
保留字
保留字是留给以后用的关键字。
| implements | interface | let | package |
|---|---|---|---|
| private | protected | public | static |
