代码编辑器：
x
1
<p id="demo"></p>2
<script>3
var x = 0.1;4
var y = 0.2;5
var z = x + y;6
document.getElementById("demo").innerHTML = z;7
</script>8
<p id="demo"></p><script>var x = 0.1;var y = 0.2;var z = x + y;document.getElementById("demo").innerHTML = z;</script>