我编写了一个PHP代码来解析数据pobidd GoogleBooks API
<?php
$isbn = "9781451648546"; // Steve Jobs book
$json = file_get_contents('https://www.googleapis.com/books/v1/volumes?q=isbn:'.$isbn);
$obj = json_decode($json, true);
echo $obj["volumeInfo"]["title"];
echo $obj["volumeInfo"]["title"];
echo $obj["volumeInfo"]["subtitle"];
echo $obj["volumeInfo"]["authors"];
echo $obj["volumeInfo"]["printType"];
echo $obj["volumeInfo"]["pageCount"];
echo $obj["volumeInfo"]["publisher"];
echo $obj["volumeInfo"]["publishedDate"];
echo $obj["accessInfo"]["webReaderLink"];
?>
执行时，我得到了
注意：未定义的索引：第8行的/storage/ssd3/164/2474164/public_html/dev/fetch/v2.php中的volumeInfo
对于所有回声字符串，所以我在没有解决方案的情况下重新检查了所有可能的问题来源
答案 0 :(得分：0)
您以错误的方式访问数组元素。请var_dump($obj);或echo '<pre>'; print_r($obj); echo '</pre>';查看完整的数组结构。您的echo语句将如下所示：
echo $obj['items'][0]["volumeInfo"]["title"] . '<br />';
// echo $obj['items'][0]["volumeInfo"]["subtitle"];
echo $obj['items'][0]["volumeInfo"]["authors"][0] . '<br />';
echo $obj['items'][0]["volumeInfo"]["printType"] . '<br />';
echo $obj['items'][0]["volumeInfo"]["pageCount"] . '<br />';
echo $obj['items'][0]["volumeInfo"]["publisher"] . '<br />';
echo $obj['items'][0]["volumeInfo"]["publishedDate"] . '<br />';
echo $obj['items'][0]["accessInfo"]["webReaderLink"] . '<br />';
不确定您是否会收到字幕信息以及图书详细信息。如果是，那么请取消注释 行。
答案 1 :(得分：0)
在我看来，使用对象表示法访问JSON响应的各种属性而不是笨重的数组语法要容易得多，但是在尝试访问子对象之前需要在对象/数组层次结构中识别正确的位置它的钥匙。
Steve JobsWalter IsaacsonBOOK
stdClass Object
(
[kind] => books#volumes
[totalItems] => 1
[items] => Array
(
[0] => stdClass Object
(
[kind] => books#volume
[id] => 8U2oAAAAQBAJ
[etag] => Cfd5hfOLjks
[selfLink] => https://www.googleapis.com/books/v1/volumes/8U2oAAAAQBAJ
[volumeInfo] => stdClass Object
(
[title] => Steve Jobs
[authors] => Array
(
[0] => Walter Isaacson
)
[publisher] => Simon and Schuster
[publishedDate] => 2011
[description] => Draws on more than forty interviews with Steve Jobs, as well as interviews with family members, friends, competitors, and colleagues to offer a look at the co-founder and leading creative force behind the Apple computer company.
[industryIdentifiers] => Array
(
[0] => stdClass Object
(
[type] => ISBN_13
[identifier] => 9781451648546
)
[1] => stdClass Object
(
[type] => ISBN_10
[identifier] => 1451648545
)
)
[readingModes] => stdClass Object
(
[text] =>
[image] =>
)
[pageCount] => 630
[printType] => BOOK
[categories] => Array
(
[0] => Biography & Autobiography
)
[averageRating] => 4
[ratingsCount] => 3904
[maturityRating] => NOT_MATURE
[allowAnonLogging] =>
[contentVersion] => 0.3.0.0.preview.0
[imageLinks] => stdClass Object
(
[smallThumbnail] => http://books.google.com/books/content?id=8U2oAAAAQBAJ&printsec=frontcover&img=1&zoom=5&edge=curl&source=gbs_api
[thumbnail] => http://books.google.com/books/content?id=8U2oAAAAQBAJ&printsec=frontcover&img=1&zoom=1&edge=curl&source=gbs_api
)
[language] => en
[previewLink] => http://books.google.co.uk/books?id=8U2oAAAAQBAJ&printsec=frontcover&dq=isbn:9781451648546&hl=&cd=1&source=gbs_api
[infoLink] => http://books.google.co.uk/books?id=8U2oAAAAQBAJ&dq=isbn:9781451648546&hl=&source=gbs_api
[canonicalVolumeLink] => https://books.google.com/books/about/Steve_Jobs.html?hl=&id=8U2oAAAAQBAJ
)
[saleInfo] => stdClass Object
(
[country] => GB
[saleability] => NOT_FOR_SALE
[isEbook] =>
)
[accessInfo] => stdClass Object
(
[country] => GB
[viewability] => PARTIAL
[embeddable] => 1
[publicDomain] =>
[textToSpeechPermission] => ALLOWED_FOR_ACCESSIBILITY
[epub] => stdClass Object
(
[isAvailable] =>
)
[pdf] => stdClass Object
(
[isAvailable] =>
)
[webReaderLink] => http://play.google.com/books/reader?id=8U2oAAAAQBAJ&hl=&printsec=frontcover&source=gbs_api
[accessViewStatus] => SAMPLE
[quoteSharingAllowed] =>
)
[searchInfo] => stdClass Object
(
[textSnippet] => Draws on more than forty interviews with Steve Jobs, as well as interviews with family members, friends, competitors, and colleagues to offer a look at the co-founder and leading creative force behind the Apple computer company.
)
)
)
)
将输出
$counter