How do “Object()” and “new Object()” differ in JavaScript?

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鱼传尺愫
鱼传尺愫 2021-02-03 12:28

In JavaScript, what\'s the difference between

var x = Object();

and

var x = new Object();

?

1条回答
  •  一生所求
    2021-02-03 12:38

    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:

    1. 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 ])

    2. 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.

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