# nlohmann::operator>>(basic_json) ```cpp std::istream& operator>>(std::istream& i, basic_json& j); ``` Deserializes an input stream to a JSON value. ## Parameters `i` (in, out) : input stream to read a serialized JSON value from `j` (in, out) : JSON value to write the deserialized input to ## Return value the stream `i` ## Exceptions - Throws [`parse_error.101`](../home/exceptions.md#jsonexceptionparse_error101) in case of an unexpected token. - Throws [`parse_error.102`](../home/exceptions.md#jsonexceptionparse_error102) if `to_unicode` fails or surrogate error. - Throws [`parse_error.103`](../home/exceptions.md#jsonexceptionparse_error103) if `to_unicode` fails. ## Complexity Linear in the length of the input. The parser is a predictive LL(1) parser. ## Notes A UTF-8 byte order mark is silently ignored. !!! warning "Deprecation" This function replaces function `#!cpp std::istream& operator<<(basic_json& j, std::istream& i)` which has been deprecated in version 3.0.0. It will be removed in version 4.0.0. Please replace calls like `#!cpp j << i;` with `#!cpp i >> j;`. ## Examples ??? example The example below shows how a JSON value is constructed by reading a serialization from a stream. ```cpp --8<-- "examples/operator_deserialize.cpp" ``` Output: ```json --8<-- "examples/operator_deserialize.output" ``` ## See also - [accept](basic_json/accept.md) - check if the input is valid JSON - [parse](basic_json/parse.md) - deserialize from a compatible input ## Version history - Added in version 1.0.0. Deprecated in version 3.0.0.