<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<body>
<script>
eval("alert('Hello')");
//简易计算器
//step1:请用户输入算数表达式
var stmt=prompt("输入算式");
//step2:将算数表达式放入eval中
var r=eval(stmt);
//step3:输出eval的计算结果
console.log(r); //
//除数为0和isFinite()
console.log(isFinite(4/2)); //true
console.log(4/2); //infinity
console.log(inFinite(4/0));false
</script>
</body>
</html>