The Object()
constructor turns the input into an object. Its behavior depends on the input's type.
The Object()
constructor turns the input into an object. Its behavior depends on the input's type.
new Object() new Object(value) Object() Object(value)
Note: Object()
can be called with or without new
, but sometimes with different effects. See Return value.
value
Optional
Any value.
When the Object()
constructor itself is called or constructed, its return value is an object:
null
or undefined
, it creates and returns an empty object.BigInt
primitive returns a BigInt
wrapper object.When Object()
is constructed but new.target
is not the Object
constructor itself, the behavior is slightly different — it initializes a new object with new.target.prototype
as its prototype. Any argument value is ignored. This may happen, for example, when Object()
is implicitly called via super()
in the constructor of a class that extends Object
. In this case, even if you pass a number to super()
, the this
value inside the constructor does not become a Number
instance.
const o = new Object(); o.foo = 42; console.log(o); // { foo: 42 }
The following examples store an empty Object
object in o
:
const o = new Object();
const o = new Object(undefined);
const o = new Object(null);
The BigInt()
and Symbol()
constructors throw an error when called with new
, to prevent the common mistake of creating a wrapper object instead of the primitive value. The only way to create a wrapper object for these types is to call Object()
with them:
const numberObj = new Number(1); console.log(typeof numberObj); // "object" const bigintObj = Object(1n); console.log(typeof bigintObj); // "object" const symbolObj = Object(Symbol("foo")); console.log(typeof symbolObj); // "object"
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Object |
1 | 12 | 1 | 3 | 1 | 18 | 4 | 10.1 | 1 | 1.0 | 4.4 | 1.0 | 0.10.0 |
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/Object