如何使用PHP来获取和解码JSON数据？

Question

如何从JSON url https://api.coinmarketcap.com/v1/ticker/ethereum/获取变量“price_usd”和“price_btc”？我写了一个脚本，但没有任何反应。

<?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

你的代码中使用的file_get_contents两次，看看会是：

<?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

试试这个

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

?>