php无法解码json对象

I have this json object that I want to get the access_token but its refusing i have no idea why . This is the response I want the access_token

{
        "access_token": "Alhq74lVl5GAOVAZrprOGSS1Gj73",
        "expires_in": "3599"
    }

This is the code

function generateToke() {
// $url = 'https://sandbox.safaricom.co.ke/oauth/v1/generate?grant_type=client_credentials';
   $url = 'https://api.safaricom.co.ke/oauth/v1/generate?grant_type=client_credentials';
   $curl = curl_init();
   curl_setopt($curl, CURLOPT_URL, $url);
   $credentials = base64_encode('qniogqzdbIskIQt9nxgxG1wSBkzgUqN0:XUjxWzQY3WTndqHh');
   curl_setopt($curl, CURLOPT_HTTPHEADER, array('Authorization: Basic ' . $credentials)); //setting a custom header
   curl_setopt($curl, CURLOPT_HEADER, false);
   curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);

   $curl_response = curl_exec($curl);
   $result = json_decode($curl_response);


   $token = $result->access_token;
   echo $token;

}

getting the same error

the above code is still displaying to me the json but i want to get only the Alhq74lVl5GAOVAZrprOGSS1Gj73

You're not accessing the access_token property of the resulting object, you try to access a property that is named in the not defined variable $access_token;.

So just remove the $-sign and it shoudl work:

$token = $result->access_token;

Furthermore you're missing a curl option to return the content:

curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

Without this option set to true you're not retrieving the response from the curl_exec call.

Change:

$token = $result->$access_token;

To (without the $ on access_token):

$token = $result->access_token;

It's not working because PHP has a feature called variable variables which you've accidentally used. PHP is trying to get the property of whatever the value of $access_token is. E.g. if a variable called $access_token was set to helloworld, PHP would run $result->helloworld and replace $access_token with it's value.