Unable to get jsonDecode in magento 2 - json

Question

Magento 1.x has its own JSON decode functions:
Mage::helper('core')->jsonDecode($array);
So how to use JSON Decode in Magento 2.

Answer 1

In the current version of Magento2 (2.2.3) the \Magento\Framework\Json\Helper\Data class is deprecated and may no longer be used in future versions. Therefore it is highly recommended to use the \Magento\Framework\Serialize\Serializer\Json class instead to decode a json string or encode an array to a json string.
/**
*
* #var \Magento\Framework\Serialize\Serializer\Json
*/
protected $_jsonSerializer;
public function __construct(
...
\Magento\Framework\Serialize\Serializer\Json $jsonSerializer,
...
) {
...
$this->_jsonSerializer = $jsonSerializer;
...
}
public function decodeJsonString($jsonString)
{
return $this->_jsonSerializer->unserialize($jsonString);
}
public function encodeArray($array)
{
return $this->_jsonSerializer->serialize($array);
}

Answer 2

Try below code with magento 2 for json decode
$objectManager = \Magento\Framework\App\ObjectManager::getInstance();
$jsonManager = $objectManager->get('\Magento\Framework\Json\Decoder');
return $jsonManager->decode($data);

Answer 3

According to This Answer
Method 1:
echo $this->helper(\Magento\Framework\Json\Helper\Data::class)->jsonDecode($array);
Or
$jsonHelper = $this->helper('Magento\Framework\Json\Helper\Data');
echo $jsonHelper->jsonDecode($array);
Method 2:
/**
* Constructor.
*
* #param \Magento\Framework\Json\Helper\Data $jsonHelper
*/
public function __construct(\Magento\Framework\Json\Helper\Data $jsonHelper)
{
$this->jsonHelper = $jsonHelper;
}
/**
* #param array $dataToDecode
* #return string
*/
public function decodeSomething(array $dataToDecode)
{
$decodedData= $this->jsonHelper->jsonDecode($dataToDecode);
return $decodedData;
}