Help Me! 6:12: error: comparison between pointer and integer ('char' and 'const char *')

[Stoney L]

Well, dudes, I'm back for another question:What deal is with this?
The error is:
tempCodeRunnerFile.cpp:6:12: error: comparison between pointer and integer ('char' and 'const char *')
So next, there is my code:
#include <iostream>
using namespace std;
int main() {
char a;
int ascii,suma,sumb,sumc;
while(a!="?"){
cin>>a;
a=ascii;
if (ascii>60&&ascii<123||ascii>64&&ascii<91){
suma=suma+1;
}
if (ascii>47&&ascii<58) {
sumb=sumb+1;
}
if (ascii>31&&ascii<48) {
sumc=sumc+1;
}
if (ascii==63) {
break;
}
}
cout<<sumb<<endl<<suma<<endl<<sumc<<endl;
return 0;
}
(Tips:I'm using Visual Studio Code.)

[dev7060]

while ( a != "?" ){

Double quotes are used for string literal. In the first iteration, a isn't initialized to a value and used for comparison in an entry-controlled loop.

a = ascii;

Why would you update a after the input?

ascii is never initialized.

Increment to suma, sumb and sumc are done without any initial value.