C ++ keywords words are also called reserve words. The meaning of these words is already defined by the compiler.
For example int age =27; where int is the keyword whose special meaning is already defined. We cannot use it as an identifier. They always begin with the small latter.
List of all possible C++ keywords in C++ 2017
| Keywords (A-C) | Keywords (C-I) | Keywords (L-S) | Keywords (S-Z) |
| alignas | continue | long | static_cast |
| alignof | co_await | module | struct |
| and | co_return | mutable | switch |
| and_eq | co_yield | namespace | synchronized |
| asm | decltype | new | template |
| atomic_cancel | default | noexcept | this |
| atomic_commit | delete | not | thread_local |
| atomic_noexcept | do | not_eq | throw |
| auto | double | nullptr | true |
| bitand | dynamic_cast | operator | try |
| bitor | else | or | typedef |
| bool | enum | or_eq | typeid |
| break | explicit | private | typename |
| case | export | protected | union |
| catch | extern | public | unsigned |
| char | false | register | using |
| char16_t | float | reinterpret_cast | virtual |
| char32_t | for | requires | void |
| class | friend | return | volatile |
| compl | goto | short | wchar_t |
| concept | if | signed | while |
| const | import | sizeof | xor |
| constexpr | inline | static | xor_eq |
| const_cast | int | static_assert |