<script> 和 </script> 标签之间.body 或者 head 部分.head 或者 body 底部.src.window.alert() 弹出警告框.document.write() 将内容写到 HTML 文档中.innerHTML 写入到 HTML 元素.console.log() 写入浏览器控制台.document.getElementByID(id)<body>
<h1 id="id">OK</h1>
<script>
document.getElementById("id").innerHTML = "what";
</script>
</body><script>document.write(Data());</script> <script>
a = 5;
b = 6;
c = a + b;
console.log(c);
</script>数字(Number)
字符串(String)
表达式(用于计算)
数组(Array)
[40, 100, 1, 5, 25, 10]对象(Object)
{firtname:"John", lastname:"Doe", age:50, eyecolor:"blue"}函数(Function)
function myFunction(a,b){return a*b;}var 或 let 定义变量.原文：https://www.cnblogs.com/_inx/p/12410377.html