JavaScript Boolean 对象的使用与转换规则

<!DOCTYPE html>
<html>
<body>
​
<script>
var b1=new Boolean(0);
var b2=new Boolean(1);
var b3=new Boolean("");
var b4=new Boolean(null);
var b5=new Boolean(NaN);
var b6=new Boolean("false");
​
document.write("0 is boolean "+ b1 +"<br>");
document.write("1 is boolean "+ b2 +"<br>");
document.write("An empty string is boolean "+ b3 + "<br>");
document.write("null is boolean "+ b4+ "<br>");
document.write("NaN is boolean "+ b5 +"<br>");
document.write("The string 'false' is boolean "+ b6 +"<br>");
</script>
​
</body>
</html> 

0 is boolean false
1 is boolean true
An empty string is boolean false
null is boolean false
NaN is boolean false
The string 'false' is boolean true

var myBoolean=new Boolean();

0
-0
null
""
false
undefined
NaN