Check if a JSON string is valid

# simdjson_is_valid

(PECL simdjson >= 2.0.0)

simdjson_is_valid — Check if a JSON string is valid

### 说明

function simdjson_is_valid(string `$json`, int `$depth` = 512): bool

Takes a JSON encoded string and returns true if it is valid.

### 参数

`json`
  The `json` string being validated. This function only works with UTF-8 encoded strings. This function validates inputs which json_decode() can decode, provided that they are less than 4 GiB long.
`depth`
  Maximum nesting depth of the structure being validated. 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.

### 返回值

Returns `true` if `json` is a valid JSON string, `false` otherwise.

### 错误／异常

If `json` is longer than 4 GiB, 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.

### 示例

示例 #1 simdjson_decode() examples

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

    var_dump(simdjson_is_valid($json));
    var_dump(simdjson_is_valid($invalidJson));

    ?>

以上示例会输出：

    bool(true)
    bool(false)

示例 #2 `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_is_valid($json, 4));
    var_dump(simdjson_is_valid($json, 3));
    ?>

以上示例会输出：

    bool(true)
    bool(false)

### 注释

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

> 注意: 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.

### 参见

- json_encode() - 对变量进行 JSON 编码
- json_decode() - 对 JSON 格式的字符串进行解码

`↑` and `↓` to navigate • `Enter` to select • `Esc` to close • `/` to open