I'm writing this project on DFA and i want to save and covert each digit of an integer saved as a string to an int array.This is the code from the function responsible for that:
int l=final_states.size();
int* temp_final;
temp_final=new int [l];
for(int i=0;i<l;i++)
{
temp_final[i]=atoi(final_states.at(i).c_str());
}
This gives me the following mistake : request for member 'c_str' in '((DFA*)this)->DFA::final_states.std::basic_string<_CharT, _Traits, _Alloc>::at<char, std::char_traits<char>, std::allocator<char> >(((std::basic_string<char>::size_type)i))', which is of non-class type 'char'|
.
So if you could tell me how to make this conversion and saving work , that would be great.
c_str()
doest not work because after callingat(i)
you've got a char not a string. I suggest you to use:Here you take an ASCII code for a char symbol and when you subtract a
'0'
you get exectly an int you need, because all the digits go in order in ASCII table.The
atoi()
function wants aconst char*
, you cannot call.c_str()
with the result of.at(i)
which is actually achar&
value.Just fix your assignment line to
Though you also might check if you really have a digit there, before putting it into your result array: