什么限制了这个JSON解析,我该怎么做才能解决它？

Question

这个问题很容易理解和证明.

这段代码工作正常:

<?php
    $title = array("dfg","sdfsdg","asfas","Sdfh","Ssdth","Csdgo");
    $title_json = json_encode($title);
?>
<script>
    var obj = JSON.parse('<?= $title_json; ?>');
    console.log(obj);
</script>

此代码不会:

<?php
    $title = array("Is President Trump still using his old Android phone?","Trump sets a dizzying WH pace in first days","Trumps White House Charm Offensive a Contrast to Solitary Obama","The inside story of a basketball teen so tall, he doesn't look real","Scientists say they are closer to making Star Wars holograms","Sperm theft lawsuit leaves appeals court weighing how much a life is worth","Call it Smunday: Heinz pushing to make Super Bowl Monday a national holiday");
    $title_json = json_encode($title);
?>
<script>
    var obj = JSON.parse('<?= $title_json; ?>');
    console.log(obj);
</script>

在控制台中输出错误:Uncaught SyntaxError: missing ) after argument list - (index):20其中第20行是带有JSON.parse的错误,如果您查看页面的源代码,则该行显示:

var obj = JSON.parse('["Is President Trump still using his old Android phone?","Trump sets a dizzying WH pace in first days","Trump's White House Charm Offensive a Contrast to Solitary Obama","The inside story of a basketball teen so tall, he doesn't look real","Scientists say they are closer to making 'Star Wars' holograms","Sperm theft lawsuit leaves appeals court weighing how much a life is worth","Call it 'Smunday': Heinz pushing to make Super Bowl Monday a national holiday"]');

您可能会注意到两个代码示例完全相同,数组甚至具有相同的长度,唯一的区别是字符串在第二个中更长.这是否意味着JSON可以解析的字符串有最大长度？

Answer 1

您的JSON数据包含'.因此,如果将该数据注入'分隔的字符串文字中,该字符串文字将过早关闭并导致语法错误.简单的例子:

var foo = '{"key": "This key's value"}';

您应该注意到,如果您查看生成JavaScript源代码.

这里没有必要使用JSON.parse.注入的JSON可以解释为JavaScript对象/数组文字:

var obj = <?= $title_json; ?>;

另请参见:如何将变量和数据从PHP传递到JavaScript？