x
 
<!DOCTYPE html>
<html>
<body>
<p>+ 运算符连接(添加)字符串。</p>
<button onclick="myFunction()">试一试</button>
<p id="demo"></p>
<script>
function myFunction() {
  var text1 = "Good ";
  var text2 = "Morning";
  var text3 = text1 + text2;
  document.getElementById("demo").innerHTML = text3;
}
</script>
</body>
</html>