title: detecting negative integer in a string
body: <p>Say I take in a string of input and I wanted to check if the user entered a negative number. </p>
  
  <pre><code>bool isNegative(string input[]) {
      int i = 0;
      if (input[i] == "-") {
          return true;
      } else {
          return false;
      }
  }
  </code></pre>
  
  <p>I tried a boolean function to check if the first character is a - sign, representing negative numbers e.g -5, -25.</p>
  
  <p>However, my Netbeans gave me this error:
  main.cpp:39:25: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]</p>
  
  <p>anyone knows what this means? </p>