title: Google Maps android API, drawing polylines in a loop
body: <p>I have two String arrays, <code>latitude</code> and <code>longitude</code>
  I want to draw polylines on the map, the <a href="https://developers.google.com/maps/documentation/android/lines#add_a_polyline" rel="nofollow">documentation</a> says, that it's as easy as pie. And it is. If I add polylines manually like this, it works:</p>
  
  <pre><code>PolylineOptions rectOptions = new PolylineOptions()
          .add(new LatLng(37.35, -122.0))
          .add(new LatLng(37.45, -122.0))
          .add(new LatLng(37.45, -122.2)) 
  </code></pre>
  
  <p>But the problem starts when I'm trying to loop adding polylines:</p>
  
  <pre><code>   rectOptions = new PolylineOptions();
      for(int i = 0; i&lt;latitude.length(); i++){
  rectOptions.add(new LatLng(Long.getLong(latitude[i]), Long.getLong(longitude[i])));
  // Log.d("coordinates", latitude[i]+"|"+longitude[i]);
      }
  </code></pre>
  
  <p>I get a <code>java.lang.NullPointerException</code> And I don't know why. I know the problem is in the <code>rectOptions.add()</code> method, because <code>Log.d("coordinates", latitude[i]+"|"+longitude[i]);</code> works fine in the same loop.</p>
  
  <p>Here's the output of LogCat:</p>
  
  <pre><code>    01-02 11:59:27.380: E/AndroidRuntime(25146): FATAL EXCEPTION: main
  01-02 11:59:27.380: E/AndroidRuntime(25146): java.lang.NullPointerException
  01-02 11:59:27.380: E/AndroidRuntime(25146):    at com.shniv.MainActivity$1.onClick(MainActivity.java:82)
  01-02 11:59:27.380: E/AndroidRuntime(25146):    at android.view.View.performClick(View.java:3519)
  01-02 11:59:27.380: E/AndroidRuntime(25146):    at android.view.View$PerformClick.run(View.java:14140)
  01-02 11:59:27.380: E/AndroidRuntime(25146):    at android.os.Handler.handleCallback(Handler.java:605)
  01-02 11:59:27.380: E/AndroidRuntime(25146):    at android.os.Handler.dispatchMessage(Handler.java:92)
  01-02 11:59:27.380: E/AndroidRuntime(25146):    at android.os.Looper.loop(Looper.java:137)
  01-02 11:59:27.380: E/AndroidRuntime(25146):    at android.app.ActivityThread.main(ActivityThread.java:4456)
  01-02 11:59:27.380: E/AndroidRuntime(25146):    at java.lang.reflect.Method.invokeNative(Native Method)
  01-02 11:59:27.380: E/AndroidRuntime(25146):    at java.lang.reflect.Method.invoke(Method.java:511)
  01-02 11:59:27.380: E/AndroidRuntime(25146):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:787)
  01-02 11:59:27.380: E/AndroidRuntime(25146):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:554)
  01-02 11:59:27.380: E/AndroidRuntime(25146):    at dalvik.system.NativeStart.main(Native Method)
  </code></pre>