Im a little confused as to what this main is doing with the arguments? is char just pointing to the first letter of an array string?
#What exactly is the point of char*
autumn grove
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keen moth
Not sure how we break this up further really.
There are argc number of arguments passed via the command line to the application.
So there is an array of argc arguments.
Each individual argument within this array is a C string, ergo a char*.
So that makes the whole array a type of char**.
You may see alternative examples where this parameter is expressed as char*[].
They are both the same however. It's just semantics.
autumn grove
whats the purpose for this... this just seems so dumb
pseudo shuttle
Do you understand pointers?
autumn grove
i understand that they point to the memory address of whatever were looking at so char* infile is pointing to the first characters address? i think
pseudo shuttle
ok, gimmie a min, ill break it down for you
basically read the type as this
C represents strings as an array of chars. The type of this is char* meaning a pointer to the first char of that array, the last byte is a null byte signifying the end of the string
as an alias think of this as a seperate type str
char** or using that alias str* is the same thing just another level up, it's an array to different instances of str which are in themselves arrays
keen moth
How main() is declared remains one of the few similarities between C and C++, I give you that.
You'd think C++ would have
int main(std::vector<std::string>> args)
Wouldn't you?
pseudo shuttle
that would make too much sense
also probably some problems with construction of std string
autumn grove
yeah i was thinking of it like that, but i just dont see why we need to pass in a file name as a char instead of just a string? is it because strings are not a primitive data type?
pseudo shuttle
C doesnt have a string type
C's string type is a char array
fun fact most programming languages are the same, they just lie to you and make up a string type
the first example that comes to mind is Rust. Rust's String type is literally the same as Vec<u8>. You used to be able to, (might still be able to, I havent looked or cared) use the equivalent of reinterpret_cast on a Vec<u8> and if it was valid utf8 it would be perfectly valid
autumn grove
yeah i understand a string can be categorized as a array of chars. but im programming in cpp i just dont see a use for it i as just curious as to why it was designed this way
verbal siren
It probably all just comes down to history, and a desire to be as backwards compatible with C, or, looking at it the other way, as accessible to existing C programmers. The other thought that harks back to my "history" comment above - the main interface was 1) inherited from C, 2) embedded in the language before any of the standard libraries were fully formed.
knotty orbit
yeah i understand a string can be categorized as a array of chars. but im progra...
string as a general term may have a few different technical meanings, for example std::string is rather importantly distinct from char*
though arguably, std::string is a wrapper for such
but for example, we also have std::wstring which is a wrapper for wchar_t not char
frankly you probably can and probably should (if you can) ignore char* and just use std::string
if your professor requires it, then I guess you have no choice, but otherwise, use std::string
knotty orbit
yeah i was thinking of it like that, but i just dont see why we need to pass in ...
to be pedantic here, you don't "pass file name as a char". most file names are more than one character long. you receive arguments (such as file names) as so called C Strings and as noted above, this is mostly a history from C that you just have to deal with. you have little choice in the matter. but there exist libs like Boost to help with command line arguments https://www.boost.org/doc/libs/1_80_0/doc/html/program_options.html
autumn grove
Thanks I appreciate the explanation
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autumn grove
!solved
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