Jquery 解析JSON以查找丢失的数据会导致错误
如果这与我之前的问题类似,我很抱歉。为什么搜索JSON解析中不存在的节点会导致其他所有有效节点失败Jquery 解析JSON以查找丢失的数据会导致错误,jquery,json,Jquery,Json,如果这与我之前的问题类似,我很抱歉。为什么搜索JSON解析中不存在的节点会导致其他所有有效节点失败 json.track.wiki.summary causes all to error json.track.name is fine if used without the previous //JSON data { "track": { "id": "434483410", "name": "Written in the Stars",
json.track.wiki.summary causes all to error
json.track.name is fine if used without the previous
//JSON data
{
"track": {
"id": "434483410",
"name": "Written in the Stars",
"mbid": "",
"url": "http://www.last.fm/music/Tinie+Tempah+(Feat.+Eric+Turner)/_/Written+in+the+Stars",
"duration": "208000",
"streamable": {
"#text": "0",
"fulltrack": "0"
},
"listeners": "108",
"playcount": "1523",
"artist": {
"name": "Tinie Tempah (Feat. Eric Turner)",
"mbid": "",
"url": "http://www.last.fm/music/Tinie+Tempah+(Feat.+Eric+Turner)"
},
"toptags": "\n "
}
}
对有效节点的后续访问将出错。消除丢失数据的请求,后续请求将起作用。在使用对象之前,必须有一种方法来测试它,这样它就不会破坏数据
这个数据就可以了
//JSON Data
{
"track": {
"id": "517047006",
"name": "Skyscraper",
"mbid": "a92f853d-ad6d-490e-a820-4cff9cc1f224",
"url": "http://www.last.fm/music/Demi+Lovato/_/Skyscraper",
"duration": "222000",
"streamable": {
"#text": "1",
"fulltrack": "0"
},
"listeners": "114757",
"playcount": "1424456",
"artist": {
"name": "Demi Lovato",
"mbid": "faf4cefb-036c-4c88-b93a-5b03dd0a0e6b",
"url": "http://www.last.fm/music/Demi+Lovato"
},
"album": {
"artist": "Demi Lovato",
"title": "Unbroken",
"mbid": "9c195a9b-2db4-4b63-9337-6d8152244742",
"url": "http://www.last.fm/music/Demi+Lovato/Unbroken",
"image": [{
"#text": "http://userserve-ak.last.fm/serve/64s/69672054.png",
"size": "small"
}, {
"#text": "http://userserve-ak.last.fm/serve/126/69672054.png",
"size": "medium"
}, {
"#text": "http://userserve-ak.last.fm/serve/174s/69672054.png",
"size": "large"
}, {
"#text": "http://userserve-ak.last.fm/serve/300x300/69672054.png",
"size": "extralarge"
}],
"@attr": {
"position": "11"
}
},
"toptags": {
"tag": [{
"name": "pop",
"url": "http://www.last.fm/tag/pop"
}, {
"name": "ballad",
"url": "http://www.last.fm/tag/ballad"
}, {
"name": "female vocalists",
"url": "http://www.last.fm/tag/female%20vocalists"
}, {
"name": "inspirational",
"url": "http://www.last.fm/tag/inspirational"
}, {
"name": "demi lovato",
"url": "http://www.last.fm/tag/demi%20lovato"
}]
},
"wiki": {
"published": "Sat, 20 Aug 2011 18:25:23 +0000",
"summary": "The Skyscraper Songfacts says: On November 1, 2010, Demi's publicist announced the Disney star had entered a treatment facility for "
physical and emotional issues,
" which was subsequently reported to include an eating disorder and self-cutting. Her first single since her stint in treatment finds the singer/actress finding strength in the wake of a fading relationship and it symbolizes her resilience in the face of her personal issues.",
"content": "The Skyscraper Songfacts says: On November 1, 2010, Demi's publicist announced the Disney star had entered a treatment facility for "
physical and emotional issues,
" which was subsequently reported to include an eating disorder and self-cutting. Her first single since her stint in treatment finds the singer/actress finding strength in the wake of a fading relationship and it symbolizes her resilience in the face of her personal issues.\n \nUser-contributed text is available under the Creative Commons By-SA License and may also be available under the GNU FDL."
}
}
}该错误不会导致其他代码失败。当第一行出错时,它将停止执行,从而永远无法到达其他代码 您可以添加如下内容:
if(json && json.track && json.track.wiki){
// do something with json.track.wiki.summary
}
如果您的json字段不固定,您必须检查json结果中是否存在这些字段。 您可以尝试以下代码来执行相同的操作:
if (typeof(json.track.wiki) != "undefined")
{
//code for what to do with json here
}
或
创建一个如下所示的函数,并传递node元素以验证其存在性(首选)
//这样称呼它
var nodevalue=isExists(json.track.wiki)
通过这样做,您可以确保在使用特定节点之前该节点已存在。这样以后的代码也能正确执行
执行上面的代码时可能会出现一些错误。所以别忘了纠正 您是否使用var data=$.parseJSON(源代码)?。您的第二组数据不是有效的JSONYes:var obj=jQuery.parseJSON(strLastFM);我一直使用JSON,因为它来自Last.FM,任何查询都会有所不同。
var nodevalue=isExists(json.track.wiki)