代码示例：（标识：eg_js_object_constructor_builtin_2）
<!DOCTYPE html>
<html>
<body>
<h1>JavaScript 对象构造器</h1>
<p id="demo"></p>
<script>
var x1 = {}; // 对象
var x2 = ""; // 字符串
var x3 = 0; // 数字
var x4 = false; // 布尔
var x5 = []; // 对象（非数组）
var x6 = /()/; // 对象
var x7 = function(){}; // 函数
// 显示所有类型
document.getElementById("demo").innerHTML =
"x1: " + typeof x1 + "<br>" +
"x2: " + typeof x2 + "<br>" +
"x3: " + typeof x3 + "<br>" +
"x4: " + typeof x4 + "<br>" +
"x5: " + typeof x5 + "<br>" +
"x6: " + typeof x6 + "<br>" +
"x7: " + typeof x7 + "<br>";
</script>
</body>
</html>
