我有这个JSON数组（从iTunes返回），我希望从中提取trackName，artistName和previewURL。我已经尝试了各种foreach次迭代，但我似乎无法正常工作。
JSON数组：
{
"resultCount": 5,
"results": [
{
"wrapperType": "track",
"kind": "song",
"artistId": 277293880,
"collectionId": 902180909,
"trackId": 902180917,
"artistName": "Lady Gaga",
"collectionName": "Born This Way (Bonus Track Version)",
"trackName": "Born This Way",
"collectionCensoredName": "Born This Way (Bonus Track Version)",
"trackCensoredName": "Born This Way",
"artistViewUrl": "https:\/\/itunes.apple.com\/us\/artist\/lady-gaga\/id277293880?uo=4",
"collectionViewUrl": "https:\/\/itunes.apple.com\/us\/album\/born-this-way\/id902180909?i=902180917&uo=4",
"trackViewUrl": "https:\/\/itunes.apple.com\/us\/album\/born-this-way\/id902180909?i=902180917&uo=4",
"previewUrl": "http:\/\/a463.phobos.apple.com\/us\/r30\/Music1\/v4\/d5\/3c\/07\/d53c0773-ff35-1fe5-9be2-815038285c08\/mzaf_4465142801402798156.plus.aac.p.m4a",
"artworkUrl30": "http:\/\/is3.mzstatic.com\/image\/thumb\/Music1\/v4\/94\/8f\/b9\/948fb9ce-de93-fe33-e7b5-a8bdf5580178\/source\/30x30bb.jpg",
"artworkUrl60": "http:\/\/is3.mzstatic.com\/image\/thumb\/Music1\/v4\/94\/8f\/b9\/948fb9ce-de93-fe33-e7b5-a8bdf5580178\/source\/60x60bb.jpg",
"artworkUrl100": "http:\/\/is3.mzstatic.com\/image\/thumb\/Music1\/v4\/94\/8f\/b9\/948fb9ce-de93-fe33-e7b5-a8bdf5580178\/source\/100x100bb.jpg",
"collectionPrice": 10.99,
"trackPrice": 1.29,
"releaseDate": "2013-01-01T08:00:00Z",
"collectionExplicitness": "notExplicit",
"trackExplicitness": "notExplicit",
"discCount": 1,
"discNumber": 1,
"trackCount": 22,
"trackNumber": 2,
"trackTimeMillis": 260258,
"country": "USA",
"currency": "USD",
"primaryGenreName": "Pop",
"isStreamable": true
},
{
"wrapperType": "track",
"kind": "song",
"artistId": 277293880,
"collectionId": 902096524,
"trackId": 902096558,
"artistName": "Lady Gaga",
"collectionName": "Born This Way",
"trackName": "Born This Way",
"collectionCensoredName": "Born This Way",
"trackCensoredName": "Born This Way",
"artistViewUrl": "https:\/\/itunes.apple.com\/us\/artist\/lady-gaga\/id277293880?uo=4",
"collectionViewUrl": "https:\/\/itunes.apple.com\/us\/album\/born-this-way\/id902096524?i=902096558&uo=4",
"trackViewUrl": "https:\/\/itunes.apple.com\/us\/album\/born-this-way\/id902096524?i=902096558&uo=4",
"previewUrl": "http:\/\/a459.phobos.apple.com\/us\/r30\/Music1\/v4\/c7\/2a\/83\/c72a8341-88b7-c65d-09dc-c333de92bb0c\/mzaf_4381737056492150878.plus.aac.p.m4a",
"artworkUrl30": "http:\/\/is1.mzstatic.com\/image\/thumb\/Music3\/v4\/b9\/d2\/e8\/b9d2e809-eb0b-d2df-193b-5bc99b5e5ecf\/source\/30x30bb.jpg",
"artworkUrl60": "http:\/\/is1.mzstatic.com\/image\/thumb\/Music3\/v4\/b9\/d2\/e8\/b9d2e809-eb0b-d2df-193b-5bc99b5e5ecf\/source\/60x60bb.jpg",
"artworkUrl100": "http:\/\/is1.mzstatic.com\/image\/thumb\/Music3\/v4\/b9\/d2\/e8\/b9d2e809-eb0b-d2df-193b-5bc99b5e5ecf\/source\/100x100bb.jpg",
"collectionPrice": 7.99,
"trackPrice": 1.29,
"releaseDate": "2011-02-11T08:00:00Z",
"collectionExplicitness": "notExplicit",
"trackExplicitness": "notExplicit",
"discCount": 1,
"discNumber": 1,
"trackCount": 14,
"trackNumber": 2,
"trackTimeMillis": 260258,
"country": "USA",
"currency": "USD",
"primaryGenreName": "Pop",
"isStreamable": true
},
{
"wrapperType": "track",
"kind": "song",
"artistId": 277293880,
"collectionId": 902180909,
"trackId": 902180935,
"artistName": "Lady Gaga",
"collectionName": "Born This Way (Bonus Track Version)",
"trackName": "The Edge of Glory",
"collectionCensoredName": "Born This Way (Bonus Track Version)",
"trackCensoredName": "The Edge of Glory",
"artistViewUrl": "https:\/\/itunes.apple.com\/us\/artist\/lady-gaga\/id277293880?uo=4",
"collectionViewUrl": "https:\/\/itunes.apple.com\/us\/album\/the-edge-of-glory\/id902180909?i=902180935&uo=4",
"trackViewUrl": "https:\/\/itunes.apple.com\/us\/album\/the-edge-of-glory\/id902180909?i=902180935&uo=4",
"previewUrl": "http:\/\/a642.phobos.apple.com\/us\/r30\/Music4\/v4\/bb\/93\/f6\/bb93f6dd-b09f-6378-9097-e41fab0a50e7\/mzaf_2685820553066586847.plus.aac.p.m4a",
"artworkUrl30": "http:\/\/is3.mzstatic.com\/image\/thumb\/Music1\/v4\/94\/8f\/b9\/948fb9ce-de93-fe33-e7b5-a8bdf5580178\/source\/30x30bb.jpg",
"artworkUrl60": "http:\/\/is3.mzstatic.com\/image\/thumb\/Music1\/v4\/94\/8f\/b9\/948fb9ce-de93-fe33-e7b5-a8bdf5580178\/source\/60x60bb.jpg",
"artworkUrl100": "http:\/\/is3.mzstatic.com\/image\/thumb\/Music1\/v4\/94\/8f\/b9\/948fb9ce-de93-fe33-e7b5-a8bdf5580178\/source\/100x100bb.jpg",
"collectionPrice": 10.99,
"trackPrice": 1.29,
"releaseDate": "2013-01-01T08:00:00Z",
"collectionExplicitness": "notExplicit",
"trackExplicitness": "notExplicit",
"discCount": 1,
"discNumber": 1,
"trackCount": 22,
"trackNumber": 17,
"trackTimeMillis": 321545,
"country": "USA",
"currency": "USD",
"primaryGenreName": "Pop",
"isStreamable": true
},
{
"wrapperType": "track",
"kind": "song",
"artistId": 277293880,
"collectionId": 902180909,
"trackId": 902180934,
"artistName": "Lady Gaga",
"collectionName": "Born This Way (Bonus Track Version)",
"trackName": "Yo\u00fc and I",
"collectionCensoredName": "Born This Way (Bonus Track Version)",
"trackCensoredName": "Yo\u00fc and I",
"artistViewUrl": "https:\/\/itunes.apple.com\/us\/artist\/lady-gaga\/id277293880?uo=4",
"collectionViewUrl": "https:\/\/itunes.apple.com\/us\/album\/yo%C3%BC-and-i\/id902180909?i=902180934&uo=4",
"trackViewUrl": "https:\/\/itunes.apple.com\/us\/album\/yo%C3%BC-and-i\/id902180909?i=902180934&uo=4",
"previewUrl": "http:\/\/a37.phobos.apple.com\/us\/r30\/Music1\/v4\/b3\/d0\/51\/b3d05174-db69-be68-272b-1b1dd35360d9\/mzaf_7395703188902498297.plus.aac.p.m4a",
"artworkUrl30": "http:\/\/is3.mzstatic.com\/image\/thumb\/Music1\/v4\/94\/8f\/b9\/948fb9ce-de93-fe33-e7b5-a8bdf5580178\/source\/30x30bb.jpg",
"artworkUrl60": "http:\/\/is3.mzstatic.com\/image\/thumb\/Music1\/v4\/94\/8f\/b9\/948fb9ce-de93-fe33-e7b5-a8bdf5580178\/source\/60x60bb.jpg",
"artworkUrl100": "http:\/\/is3.mzstatic.com\/image\/thumb\/Music1\/v4\/94\/8f\/b9\/948fb9ce-de93-fe33-e7b5-a8bdf5580178\/source\/100x100bb.jpg",
"collectionPrice": 10.99,
"trackPrice": 1.29,
"releaseDate": "2011-05-23T07:00:00Z",
"collectionExplicitness": "notExplicit",
"trackExplicitness": "notExplicit",
"discCount": 1,
"discNumber": 1,
"trackCount": 22,
"trackNumber": 16,
"trackTimeMillis": 307364,
"country": "USA",
"currency": "USD",
"primaryGenreName": "Pop",
"isStreamable": true
},
{
"wrapperType": "track",
"kind": "song",
"artistId": 277293880,
"collectionId": 716415763,
"trackId": 716415953,
"artistName": "Lady Gaga",
"collectionName": "NOW That's What I Call a Workout",
"trackName": "Born This Way (Bimbo Jones Club Remix)",
"collectionCensoredName": "NOW That's What I Call a Workout",
"trackCensoredName": "Born This Way (Bimbo Jones Club Remix)",
"collectionArtistId": 4035426,
"collectionArtistName": "Various Artists",
"artistViewUrl": "https:\/\/itunes.apple.com\/us\/artist\/lady-gaga\/id277293880?uo=4",
"collectionViewUrl": "https:\/\/itunes.apple.com\/us\/album\/born-this-way-bimbo-jones-club-remix\/id716415763?i=716415953&uo=4",
"trackViewUrl": "https:\/\/itunes.apple.com\/us\/album\/born-this-way-bimbo-jones-club-remix\/id716415763?i=716415953&uo=4",
"previewUrl": "http:\/\/a294.phobos.apple.com\/us\/r30\/Music3\/v4\/25\/47\/e8\/2547e80d-c74c-7cf4-7905-041c7f7ec259\/mzaf_1883593890824568199.plus.aac.p.m4a",
"artworkUrl30": "http:\/\/is4.mzstatic.com\/image\/thumb\/Music6\/v4\/a5\/ed\/99\/a5ed99e5-ca11-2a34-a72d-e86b2e11a1ba\/source\/30x30bb.jpg",
"artworkUrl60": "http:\/\/is4.mzstatic.com\/image\/thumb\/Music6\/v4\/a5\/ed\/99\/a5ed99e5-ca11-2a34-a72d-e86b2e11a1ba\/source\/60x60bb.jpg",
"artworkUrl100": "http:\/\/is4.mzstatic.com\/image\/thumb\/Music6\/v4\/a5\/ed\/99\/a5ed99e5-ca11-2a34-a72d-e86b2e11a1ba\/source\/100x100bb.jpg",
"collectionPrice": 11.99,
"trackPrice": -1,
"releaseDate": "2012-12-18T08:00:00Z",
"collectionExplicitness": "notExplicit",
"trackExplicitness": "notExplicit",
"discCount": 1,
"discNumber": 1,
"trackCount": 18,
"trackNumber": 1,
"trackTimeMillis": 284453,
"country": "USA",
"currency": "USD",
"primaryGenreName": "Fitness & Workout",
"isStreamable": false
}
]
}
例如，我尝试了以下方面的内容：
foreach($obj['results'] as $row => $value) {
foreach($value['trackName'] as $type => $output) {
echo $output . "/n";
}
}
其中$ obj是json_decode的结果。我认为我的大脑今天只是炒了，因为我觉得它并不那么难，但我们就是这样。