Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
For example, the character ‘a’ (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
char is already an integer type in C++, and it gets automatically promoted to int. So you can use a character where you would otherwise use an integer. Conversely, you can use an integer where you would normally use a character, except you may need to cast it, as char is smaller.
In this case, the output operator << is overloaded to handle integer (outputs the decimal representation) and character (outputs just the character) types differently, so we need to cast it in both cases.
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