ObjectId
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Description
ObjectId( <hexadecimal> )-
Returns a new ObjectId value. The 12-byte ObjectId value consists of:
- a 4-byte timestamp value, representing the ObjectId’s creation, measured in seconds since the Unix epoch
- a 5-byte random value
- a 3-byte incrementing counter, initialized to a random value
While the BSON format itself is little-endian, the timestamp and counter values are big-endian, with the most significant bytes appearing first in the byte sequence.
ObjectId()can accept the following parameter:Field Type Description hexadecimalString 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")