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- ObjectId
ObjectId¶
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Description¶
- ObjectId(<hexadecimal>)¶
Returns a new ObjectId value. The 12-byte ObjectId value consists of:
- a 4-byte value representing the seconds since the Unix epoch,
- a 3-byte machine identifier,
- a 2-byte process id, and
- a 3-byte counter, starting with a random value.
ObjectId() can accept the following parameter:
Field Type Description hexadecimal String Optional. Hexadecimal string value for the new ObjectId.
Methods and Attributes¶
ObjectId() has the following attribute and methods:
| Attribute/Method | Description |
|---|---|
| str | Returns the hexadecimal string representation of the object. |
| ObjectId.getTimestamp() | Returns the timestamp portion of the object as a Date. |
| ObjectId.toString() | Returns the JavaScript representation in the form of a string literal “ObjectId(...)”. |
| ObjectId.valueOf() | Returns the representation of the object as a hexadecimal string. The returned string is the str attribute. |
Examples¶
Generate a New ObjectId¶
To generate a new ObjectId, use ObjectId() with no argument:
x = ObjectId()
In this example, the value of x would be:
ObjectId("507f1f77bcf86cd799439011")
Specify a Hexadecimal String¶
To generate a new ObjectId using ObjectId() with a unique hexadecimal string:
y = ObjectId("507f191e810c19729de860ea")
In this example, the value of y would be:
ObjectId("507f191e810c19729de860ea")
Access the Hexadecimal String¶
Access the str attribute of an ObjectId() object, as follows:
ObjectId("507f191e810c19729de860ea").str
This operation will return the following hexadecimal string:
507f191e810c19729de860ea