simdjson_decode

Decodes a JSON string

&reftitle.description; `mixed` `simdjson_decode` `string` `json` `bool` `associative`&false; `int` `depth` 512

Takes a JSON encoded string and converts it into a PHP value. This uses a faster Simultaneous Instruction, Multiple Data implementation than `json_decode` when it is supported by the computer architecture.

&reftitle.parameters;

`json`

- The `json` `string` being decoded.

  This function only works with UTF-8 encoded strings.

  This function parses valid inputs which `json_decode` can decode, provided that they are less than 4 GiB long.

`associative`

- When &true;, JSON objects will be returned as associative &array;s; when &false;, JSON objects will be returned as &object;s.

`depth`

- Maximum nesting depth of the structure being decoded. The value must be greater than `0`, and less than or equal to `2147483647`. Callers should use reasonably small values, because larger depths require more buffer space and will increase the recursion depth, unlike the current `json_decode` implementation.

&reftitle.returnvalues;

Returns the value encoded in `json` in appropriate PHP type. Values `true`, `false` and `null` are returned as &true;, &false; and &null; respectively.

&reftitle.errors;

If `json` is invalid, a `SimdJsonException` is thrown as of PECL simdjson 2.1.0, while previously, a `RuntimeException` was thrown.

If `depth` is outside the allowed range, a `SimdJsonValueError` is thrown as of PECL simdjson 3.0.0, while previously, an error of level `E_WARNING` was raised.

&reftitle.examples;

### `simdjson_decode` examples

    <?php
    $json = '{"a":1,"b":2,"c":3}';

    var_dump(simdjson_decode($json));
    var_dump(simdjson_decode($json, true));

    ?>

&example.outputs;

    object(stdClass)#1 (3) {
      ["a"]=>
      int(1)
      ["b"]=>
      int(2)
      ["c"]=>
      int(3)
    }
    array(3) {
      ["a"]=>
      int(1)
      ["b"]=>
      int(2)
      ["c"]=>
      int(3)
    }

### Accessing invalid object properties

Accessing elements within an object that contain characters not permitted under PHP's naming convention (e.g. the hyphen) can be accomplished by encapsulating the element name within braces and the apostrophe.

    <?php

    $json = '{"foo-bar": 12345}';

    $obj = simdjson_decode($json);
    print $obj->{'foo-bar'}; // 12345

    ?>

### common mistakes using `simdjson_decode`

    <?php

    // the following strings are valid JavaScript but not valid JSON

    // the name and value must be enclosed in double quotes
    // single quotes are not valid
    $bad_json = "{ 'bar': 'baz' }";
    simdjson_decode($bad_json); // Throws SimdJsonException

    // the name must be enclosed in double quotes
    $bad_json = '{ bar: "baz" }';
    simdjson_decode($bad_json); // Throws SimdJsonException

    // trailing commas are not allowed
    $bad_json = '{ bar: "baz", }';
    simdjson_decode($bad_json); // Throws SimdJsonException

    ?>

### `depth` errors

    <?php
    // Encode some data with a maximum depth of 4
    // (array -> array -> array -> string)
    $json = json_encode(
        [
            1 => [
                'English' => [
                    'One',
                    'January'
                ],
                'French' => [
                    'Une',
                    'Janvier'
                ]
            ]
        ]
    );

    // Show the errors for different depths.
    var_dump(simdjson_decode($json, true, 4));
    try {
        var_dump(simdjson_decode($json, true, 3));
    } catch (SimdJsonException $e) {
         echo "Caught: ", $e->getMessage(), "\n";
    }
    ?>

&example.outputs;

    array(1) {
      [1]=>
      array(2) {
        ["English"]=>
        array(2) {
          [0]=>
          string(3) "One"
          [1]=>
          string(7) "January"
        }
        ["French"]=>
        array(2) {
          [0]=>
          string(3) "Une"
          [1]=>
          string(7) "Janvier"
        }
      }
    }
    Caught: The JSON document was too deep (too many nested objects and arrays)

### `simdjson_decode` of large integers

    <?php
    $json = '{"number": 12345678901234567890}';

    var_dump(simdjson_decode($json));

    ?>

&example.outputs;

    object(stdClass)#1 (1) {
      ["number"]=>
      float(1.2345678901235E+19)
    }

&reftitle.notes;

The JSON spec is not JavaScript, but a subset of JavaScript.

In the event of a failure to decode, a `SimdJsonException` is thrown and `SimdJsonException::getCode` and `SimdJsonException::getMessage` can be used to determine the exact nature of the error.

&reftitle.seealso;

- `json_encode`
- `json_decode`