Question

When programming in C, is it possible to set a const with a value of a user-input?
If so, how?

Answer 1

Why not?

void some_function(int user_input)
{
    const int const_user_input = user_input;
    ...
    return;
}

int main (void)
{
    int user_input;
    scanf("%d", &user_input);
    some_function(user_input);
    return 0;
}