# MongoDB\BSON\toJSON

(mongodb >=1.0.0)

MongoDB\BSON\toJSON — Returns the Legacy Extended JSON representation of a BSON value

### 说明

MongoDB\BSON\toJSON ( string `$bson` ) : string

Converts a BSON string to its » Legacy Extended JSON representation.

> Note: There exist several JSON formats for representing BSON. This function implements the "strict mode" defined in » MongoDB Extended JSON, which has been superseded by the canonical and relaxed formats defined in the » Extended JSON Specification and implemented by MongoDB\BSON\toCanonicalExtendedJSON() and MongoDB\BSON\toRelaxedExtendedJSON(), respectively.

Warning

» JSON does not support `NAN` and `INF` and MongoDB's Legacy Extended JSON format does not define an alternative representation for these values (» libbson will output nan and inf literals, which may not be parsed as valid JSON). If you are working with BSON that may contain non-finite numbers, please use MongoDB\BSON\toCanonicalExtendedJSON() or MongoDB\BSON\toRelaxedExtendedJSON().

### 参数

`bson` (string)

  BSON value to be converted.

### 返回值

The converted JSON value.

### 错误／异常

- Throws MongoDB\Driver\Exception\UnexpectedValueException if the input did not contain exactly one BSON document. Possible reasons include, but are not limited to, invalid BSON, extra data (after reading one BSON document), or an unexpected » libbson error.

### 范例

Example #1 MongoDB\BSON\toJSON() example

    <?php

    $documents = [
        [ 'null' => null ],
        [ 'boolean' => true ],
        [ 'string' => 'foo' ],
        [ 'int32' => 123 ],
        [ 'int64' => 4294967295 ],
        [ 'double' => 1.0, ],
        [ 'nan' => NAN ],
        [ 'pos_inf' => INF ],
        [ 'neg_inf' => -INF ],
        [ 'array' => [ 'foo', 'bar' ]],
        [ 'document' => [ 'foo' => 'bar' ]],
        [ 'oid' => new MongoDB\BSON\ObjectId('56315a7c6118fd1b920270b1') ],
        [ 'dec128' => new MongoDB\BSON\Decimal128('1234.5678') ],
        [ 'binary' => new MongoDB\BSON\Binary('foo', MongoDB\BSON\Binary::TYPE_GENERIC) ],
        [ 'date' => new MongoDB\BSON\UTCDateTime(1445990400000) ],
        [ 'timestamp' => new MongoDB\BSON\Timestamp(1234, 5678) ],
        [ 'regex' => new MongoDB\BSON\Regex('pattern', 'i') ],
        [ 'code' => new MongoDB\BSON\Javascript('function() { return 1; }') ],
        [ 'code_ws' => new MongoDB\BSON\Javascript('function() { return a; }', ['a' => 1]) ],
        [ 'minkey' => new MongoDB\BSON\MinKey ],
        [ 'maxkey' => new MongoDB\BSON\MaxKey ],
    ];

    foreach ($documents as $document) {
        $bson = MongoDB\BSON\fromPHP($document);
        echo MongoDB\BSON\toJSON($bson), "\n";
    }

    ?>

以上例程会输出：

    { "null" : null }
    { "boolean" : true }
    { "string" : "foo" }
    { "int32" : 123 }
    { "int64" : 4294967295 }
    { "double" : 1.0 }
    { "nan" : nan }
    { "pos_inf" : inf }
    { "neg_inf" : -inf }
    { "array" : [ "foo", "bar" ] }
    { "document" : { "foo" : "bar" } }
    { "oid" : { "$oid" : "56315a7c6118fd1b920270b1" } }
    { "dec128" : { "$numberDecimal" : "1234.5678" } }
    { "binary" : { "$binary" : "Zm9v", "$type" : "00" } }
    { "date" : { "$date" : 1445990400000 } }
    { "timestamp" : { "$timestamp" : { "t" : 5678, "i" : 1234 } } }
    { "regex" : { "$regex" : "pattern", "$options" : "i" } }
    { "code" : { "$code" : "function() { return 1; }" } }
    { "code_ws" : { "$code" : "function() { return a; }", "$scope" : { "a" : 1 } } }
    { "minkey" : { "$minKey" : 1 } }
    { "maxkey" : { "$maxKey" : 1 } }

### 参见

- MongoDB\BSON\fromJSON() - Returns the BSON representation of a JSON value
- MongoDB\BSON\toCanonicalExtendedJSON() - Returns the Canonical Extended JSON representation of a BSON value
- MongoDB\BSON\toRelaxedExtendedJSON() - Returns the Relaxed Extended JSON representation of a BSON value
- » MongoDB Extended JSON
- » MongoDB BSON