Printjson

Printjson is a built-in function in the MongoDB shell (classic mongo and modern mongosh) used to display objects as a human-readable, JSON-like representation. It is commonly used to inspect documents, query results, or other values during interactive scripting and debugging.

The function outputs multi-line, indented JSON-like text. It preserves BSON-specific types by rendering them as their constructor forms, such as ObjectId("..."), ISODate("..."), or BinData(...), rather than converting everything to plain JSON. Strings and keys are quoted, and the output is suitable for reading by humans rather than for strict data interchange.

Usage: You can pass a JavaScript object to printjson, or use it to display the result of a query. For example: printjson(db.users.findOne({name: "Alice"})); var d = db.products.findOne({sku: "X123"}); printjson(d);

Relationship to other functions: Printjson is similar to tojson in that both provide a JSON-like representation, but printjson is designed for pretty printing to the shell. Note that the output is not strictly valid JSON because of the BSON constructors.

Limitations and scope: It is intended for debugging and presentation, not for programmatic data exchange. In newer shells, you can also use tojson() or JSON.stringify for JSON-focused output, depending on the environment.

See also: tojson, JSON.stringify, ObjectId, ISODate.