ESP8266 webserver question

ok i am working on a networked device using the ESP8266WebServer.h plugin however i have a couple issues mainly i can't get the html to display the status of the digital pins and

i am hoping that someone can help me out

this is the piece of code i have in place to print the pin status

webPage += digitalRead(4);

Thanks,
Yonu

this is the piece of code i have in place to print the pin status

webPage += digitalRead(4);

What is adding a 0 or a 1 to the (I assume that webPage is a) String instance supposed to do?

   if(digitalRead(4) == HIGH)
      webPage += "On";
   else
      webPage += "Off";