如何使用PHP來獲取和解碼JSON數據？

Question

如何從JSON url https://api.coinmarketcap.com/v1/ticker/ethereum/獲取變量「price_usd」和「price_btc」？我寫了一個腳本，但沒有任何反應。

<?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; 
?> 

Answer 1

你的代碼中使用的file_get_contents兩次，看看會是：

<?php 
$tick = file_get_contents('https://api.coinmarketcap.com/v1/ticker/ethereum/'); 
$url = $tick; 
echo $url; 
//$json = file_get_contents($url); 
$data = json_decode($tick, TRUE); 

$usd = $data[0]["price_usd"]; 
echo $usd; 
?> 

Answer 2

試試這個

<?php 
$json = file_get_contents('https://api.coinmarketcap.com/v1/ticker/ethereum/'); 
$data = json_decode($json); 
var_dump($data[0]->price_usd); 

?>