How can I get variables "price_usd" and "price_btc" from JSON url https://api.coinmarketcap.com/v1/ticker/ethereum/? I wrote a script but nothing happens.
<?php
$tick = file_get_contents('https://api.coinmarketcap.com/v1/ticker/ethereum/');
$url = $tick;
$json = file_get_contents($url);
$data = json_decode($json, TRUE);
$usd = $data[0]["price_usd"];
echo $usd;
?>