代码示例:(标识:jsck_infinity)
<!DOCTYPE html>
<html>
<body>

<p>1.797693134862315E+308 是浮点数的极限。</p>

<p>请点击按钮来亲自查看。</p>

<button onclick="myFunction()">试一试</button>

<p id="demo"></p>

<script>
function myFunction() {  
  document.getElementById("demo").innerHTML = 
  1.7976931348623157E+10308 + "<br>" +  -1.7976931348623157E+10308;
}
</script>

</body>
</html>
运行结果: