Decodes a complex JSON string and converted into associative arrays using php

Call a API 

 $jsonurl = "https://api.coindesk.com/v1/bpi/currentprice/USD.json";  
 $json = file_get_contents($jsonurl); 
 echo var_dump(json_decode($json)); 

Which will return this

 object(stdClass)[5]  
  public 'time' =>   
   object(stdClass)[6]  
    public 'updated' => string 'May 29, 2016 06:05:00 UTC' (length=25)  
    public 'updatedISO' => string '2016-05-29T06:05:00+00:00' (length=25)  
    public 'updateduk' => string 'May 29, 2016 at 07:05 BST' (length=25)  
  public 'disclaimer' => string 'This data was produced from the CoinDesk Bitcoin Price Index (USD). Non-USD currency data converted using hourly conversion rate from openexchangerates.org' (length=155)  
  public 'bpi' =>   
   object(stdClass)[7]  
    public 'USD' =>   
     object(stdClass)[8]  
      public 'code' => string 'USD' (length=3)  
      public 'rate' => string '519.1350' (length=8)  
      public 'description' => string 'United States Dollar' (length=20)  
      public 'rate_float' => float 519.135  

Or as plain json return

 {"time":{"updated":"May 29, 2016 03:59:00 UTC","updatedISO":"2016-05-29T03:59:00+00:00","updateduk":"May 29, 2016 at 04:59 BST"},"disclaimer":"This data was produced from the CoinDesk Bitcoin Price Index (USD). Non-USD currency data converted using hourly conversion rate from openexchangerates.org","bpi":{"USD":{"code":"USD","rate":"516.4050","description":"United States Dollar","rate_float":516.405}}}  

Now we want to get data as associative arrays

 $jsonurl = "https://api.coindesk.com/v1/bpi/currentprice/USD.json";  
 $json = file_get_contents($jsonurl);  
 $obj = json_decode($json);  
 echo $obj->bpi->USD->{'rate'}; // show the rate