title: Invalid conversion from 'char' to 'const Char*' in C++
body: <p>I have declared a function (C++)</p>
  
  <pre><code>int products(char num1, char num2, char num3, char num4, char num5);
  </code></pre>
  
  <p>but my compiler is giving me this error:</p>
  
  <pre><code>Invalid conversion from 'char' to 'const Char*'
  error initializing argument 1 of 'int atoi (const char*)'  on line 22
  </code></pre>
  
  <p>when I attempt to pass <code>num1</code>, <code>num2</code> etc. as a parameter to <code>atoi</code>.</p>
  
  <pre><code>#include&lt;iostream&gt;
  #include&lt;string&gt;
  
  using namespace std;
  
  int Product(char num1, char num2, char num3, char num4, char num5);
  
  const string LargeNum = "7316717653133062491922511967442657474235534919493496983520312774506326239578318016984801869478851843858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522744304355766896648950445244523161731856403098711121722383113622298934233803081353362766142828064444866452387493035890729629049156044077239071381051585930796086670172427121883998797908792274921901699720888093776657273330010533678812202354218097512545405947522435258490771167055601360483958644670632441572215539753697817977846174064955149290862569321978468622482839722413756570560574902614079729686524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054421750694165896040807198403850962455444362981230987879927244284909188845801561660979191338754992005240636899125607176060588611646710940507754100225698315520005593572972571636269561882670428252483600823257530420752963450";
  
  int main(){
  int greatestVal = 0;
  for(int i = 0; i + 4 &lt;= LargeNum.length(); i++ ){
      if(greatestVal &lt; Product(LargeNum[i], LargeNum[i+1], LargeNum[i+2], LargeNum[i+3], LargeNum[i+4])){
          greatestVal = Product(LargeNum[i], LargeNum[i+1], LargeNum[i+2], LargeNum[i+3], LargeNum[i+4]);
      }
  }
  cout &lt;&lt; greatestVal &lt;&lt; endl;
  system("PAUSE");
  }
  
  int Product(char num1, char num2, char num3, char num4, char num5){
      return (atoi(num1)*atoi(num2)*atoi(num3)*atoi(num4)*atoi(num5));
  }
  </code></pre>