console 命令行工具 X clear

console

var person = {
  firstName: "zhang",
  lastName: "ziqiang",
  age: 50,
  eyeColor: "blue"
};
document.getElementById("demo").innerHTML = person.firstName + "现在" + person.age + "岁。";

var person = {
  firstName: "John",
  lastName: "Doe",
  age: 50,
  eyeColor: "blue"
};
document.getElementById("demo").innerHTML = person.firstName + " 现在 " + person.age + " 岁。";

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