I am creating a home weather station but the Arduino IDE shows

"expected ';' before 'viewport'". 

It detects wrong quotation marks. My code:

     String message2 = "<!DOCTYPE html>";
  message2 += "<head>";
  message2 +=  "<title>Bootstrap Example</title>";
  message2 += " <meta name="viewport" content="width=device-width, initial-scale=1">";
  message2 += "<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">";
  message2 +=  "<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>";
  message2 +=  "<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>";
  message2 += "</head>";
  message2 += "<body>";
  message2 += "<div class="container">";
  message2 +=  "<h2>Teplotná Stanica</h2>";
  message2 +=  "<p>Teplota:";
  message2 +=  dht.readTemperature();
  message2 +=  "</p>";

  server.send(200, "text/html", message2);}

Can someone tell me what´s wrong? I am using Arduino IDE

  • 1
    Have you looked at your quotes yet? All of them? Nov 12, 2017 at 15:04
  • I wonder who upvoted this question.
    – user31481
    Nov 13, 2017 at 15:14
  • Your question has been answered. Please, accept the answer to close this question.
    – user31481
    Nov 17, 2017 at 9:31

1 Answer 1


In C you can not use quotation marks inside quotation marks (thus nested).


message2 += " <meta name="viewport" content="width=device-width, initial-scale=1">";


message2 += " <meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">";

By using the escape character \ it means that \" is a character (") instead of the beginning or start of a string.

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