If JSON is null - PHP

本文关键字：PHP null is JSON If | 更新日期: 2023-09-27

这是我完整的脚本。我想做的是将$bg设置为如果URL的响应为"null"，则设为"none.jpg"。如果响应是其他东西，设置$bg，就像我在这个脚本中已经做的那样。

$backgroundURL = 'http://api.fanart.tv/webservice/artist/a93e666f14a34d979b3e3617eab2f340/6b1cf581-17a9-42c3-927b-d1e2797b1695/json/artistbackground/1/1';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $backgroundURL);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (compatible; curl)");
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
$json = curl_exec($ch);
curl_close($ch);
$json  = json_decode($json);
$first = current($json);
$bg    = $first->artistbackground[0]->url;

这就是你要找的:

if('null'==$json){
  echo 'Nothing here!';   
} else {
  echo 'Yep, found it!';
}

如果结果确实包含文字字符串 "null"，那么您必须比较该字符串，而不是与语言结构NULL进行比较。

考虑到你下面的评论，我测试了你的脚本，并添加了一个如上所述的条件。

<?php
$backgroundURL = 'http://api.fanart.tv/webservice/artist/a93e666f14a34d979b3e3617eab2f340/6b1cf581-17a9-42c3-927b-d1e2797b1695/json/artistbackground/1/1';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $backgroundURL);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (compatible; curl)");
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
$json = curl_exec($ch);
curl_close($ch);
if ('null'==$json) {
  echo "reply is 'null''n";
} else {
  echo "reply is NOT 'null''n";
}
?>

输出如预期:reply is 'null'…