How do "Object()" and "new Object()" differ in JavaScript?
In JavaScript, what's the difference between
var x = Object();
and
var x =开发者_StackOverflow中文版 new Object();
?
This is pulled directly from the ECMAScript specification:
15.2.1 The Object Constructor Called as a Function
When Object is called as a function rather than as a constructor, it performs a type conversion.
15.2.1.1 Object ( [ value ] )
When the Object function is called with no arguments or with one argument value, the following steps are taken:
If value is null, undefined or not supplied, create and return a new Object object exactly as if the standard built-in Object constructor had been called with the same arguments (15.2.2.1).
In Short:
new Object([ value ])
Return ToObject(value).
Notes:
[ ] Is A common way to mark a parameter as optional.
ToObject Is a very simple operation that is defined in section 9.9.
精彩评论