我有一个像这样的json文件。它包含了一年中流行的歌曲。我将使用这些歌曲来创建基于十年的播放列表。
{
"1940": [
{
"artist": "Tommy Dorsey",
"title": "I'll Never Smile Again"
},
{
"artist": "Bing Crosby",
"title": "Only Forever"
},
{
"artist": "Artie Shaw",
"title": "Frenesi"
},
{
"artist": "Glenn Miller",
"title": "The Nearness of You"
},
{
"artist": "Artie Shaw",
"title": "Frenesi"
},
{
"artist": "Tommy Dorsey & Frank Sinatra",
"title": "Imagination"
},
{
"artist": "Cliff Edwards (Ukelele Ike)",
"title": "When You Wish Upon a Star"
},
{
"artist": "Bing Crosby",
"title": "Sierra Sue"
},
{
"artist": "The Ink Spots",
"title": "Java Jive"
},
{
"artist": "Jimmy Dorsey",
"title": "6 Lessons From Madame La Zonga"
},
{
"artist": "Jimmie Davis",
"title": "You Are My Sunshine"
},
{
"artist": "Bob Wills & his Texas Playboys",
"title": "New San Antonio Rose"
},
{
"artist": "Tommy Dorsey",
"title": "Stardust"
},
{
"artist": "The Andrews Sisters",
"title": "Beat Me Daddy, Eight To The Bar"
},
{
"artist": "Charlie Barnet",
"title": "Pompton Turnpike"
},
{
"artist": "Judy Garland",
"title": "I'm Nobody's Baby"
},
{
"artist": "Bob Crosby & his Orchestra",
"title": "Down Argentina Way"
},
{
"artist": "Kate Smith",
"title": "The Woodpecker Song"
},
{
"artist": "Shep Fields & his Rippling Rhythm Orchestra",
"title": "Down Argentina Way"
},
{
"artist": "Vaughn Monroe",
"title": "There I Go"
},
{
"artist": "Will Bradley",
"title": "There I Go"
},
{
"artist": "Mitchell Ayres & his Fashions in Music",
"title": "Make Believe Island"
},
{
"artist": "Joe Loss Orchestra",
"title": "Beer Barrel Polka (Roll out the Barrel)"
},
{
"artist": "Carson Robison",
"title": "South of the Border (Down Mexico Way)"
},
{
"artist": "Francisco Alves",
"title": "Dama das Camelias"
},
{
"artist": "Duke Ellington",
"title": "Ko Ko"
},
{
"artist": "Bill Monroe",
"title": "Mule Skinner Blues"
},
{
"artist": "Bukka White",
"title": "Special Stream Line"
},
{
"artist": "Tony Martin",
"title": "It's a Blue World"
},
{
"artist": "Orlando Silva",
"title": "Suplica"
},
{
"artist": "Ella Fitzgerald",
"title": "Five O'Clock Whistle"
},
{
"artist": "Edith Piaf",
"title": "L'accordeoniste"
},
{
"artist": "Erskine Hawkins",
"title": "Dolemite"
},
{
"artist": "Dick Robertson & his Orchestra",
"title": "Ma (He's Making Eyes At Me)"
},
{
"artist": "Kay Kyser",
"title": "Playmates"
},
{
"artist": "Nat Gonella",
"title": "I'm Nobody's Baby"
},
{
"artist": "Bando da Lua",
"title": "O Samba da Minha Terra"
},
{
"artist": "Cyro Monteiro",
"title": "Oh! Seu Oscar"
},
{
"artist": "Roland Hayes",
"title": "Were You There?"
},
{
"artist": "Benny Goodman",
"title": "Seven Come Eleven"
},
{
"artist": "Sammy Kaye",
"title": "Dream Valley"
},
{
"artist": "Bob Chester & his Orchestra",
"title": "Practice Makes Perfect"
},
{
"artist": "Frank Proffitt",
"title": "Tom Dooley"
},
{
"artist": "Art Tatum",
"title": "Sweet Lorraine"
},
{
"artist": "Dircinha Batista",
"title": "Upa! Upa! (Meu Trolinho)"
},
{
"artist": "Connee Boswell",
"title": "On the Isle of May"
},
{
"artist": "Aracy de Almeida",
"title": "Passarinho do Relogio (Cuco)"
}
],
"1941": [
{
"artist": "Glenn Miller",
"title": "Chattanooga Choo Choo"
},
{
"artist": "Artie Shaw",
"title": "Frenesi"
},
{
"artist": "Jimmy Dorsey",
"title": "Blue Champagne"
},
{
"artist": "Sammy Kaye",
"title": "Daddy"
},
{
"artist": "Freddy Martin",
"title": "Piano Concerto in B Flat"
},
{
"artist": "Glenn Miller",
"title": "Adios"
},
{
"artist": "Sammy Kaye",
"title": "Daddy"
},
{
"artist": "Artie Shaw",
"title": "Blues in the Night"
},
{
"artist": "Billie Holiday",
"title": "God Bless the Child"
},
{
"artist": "Jimmy Dorsey",
"title": "Jim"
},
{
"artist": "The Andrews Sisters",
"title": "I'll Be With You in Apple Blossom Time"
},
{
"artist": "Duke Ellington",
"title": "I Got it Bad & That Ain't Good"
},
{
"artist": "Horace Heidt",
"title": "G'bye Now"
},
{
"artist": "Freddy Martin",
"title": "The Hut Sut Song (A Swedish Serenade)"
},
{
"artist": "The Ink Spots",
"title": "I Don't Want to Set the World On Fire"
},
{
"artist": "Harry James",
"title": "Music Makers"
},
{
"artist": "Tommy Dorsey & Frank Sinatra",
"title": "This Love of Mine"
},
{
"artist": "The Sons of the Pioneers",
"title": "Cool Water"
},
{
"artist": "Benny Goodman",
"title": "Solo Flight"
},
{
"artist": "Xavier Cugat",
"title": "Chica, Chica, Boom, Chic"
},
{
"artist": "Ernest Tubb",
"title": "Walking the Floor Over You"
},
{
"artist": "Guy Lombardo",
"title": "And the Band Played On"
},
{
"artist": "Vera Lynn",
"title": "A Nightingale Sang in Berkeley Square"
},
{
"artist": "Dick Robertson",
"title": "Ferryboat Serenade"
},
{
"artist": "The Jesters",
"title": "It's a Great Day for the Irish"
},
{
"artist": "The Tic-Toc Rhythm Orchestra",
"title": "Ferryboat Serenade"
},
{
"artist": "Judy Garland",
"title": "It's a Great Day for the Irish"
},
{
"artist": "Francisco Alves",
"title": "Canta Brasil"
},
{
"artist": "George Formby",
"title": "Bless 'em All (The Service Song)"
},
{
"artist": "Al Bowlly",
"title": "When That Man is Dead & Gone"
},
{
"artist": "Bing Crosby",
"title": "Shepherd's Serenade"
},
{
"artist": "Tommy Dorsey",
"title": "Do I Worry?"
},
{
"artist": "Charlie Barnet",
"title": "I Hear A Rhapsody"
},
{
"artist": "Wayne King",
"title": "You Are My Sunshine"
},
{
"artist": "Gene Krupa",
"title": "It All Comes Back To Me Now"
},
{
"artist": "Big Maceo Merriweather",
"title": "Worried Life Blues"
},
{
"artist": "Big Bill Broonzy",
"title": "Key to the Highway"
},
{
"artist": "Joe Loss Orchestra",
"title": "'V' Stands For Victory"
},
{
"artist": "Carlos Galhardo",
"title": "Ala Li La"
},
{
"artist": "Tommy Tucker",
"title": "I Don't Want to Set the World On Fire"
},
{
"artist": "Kay Kyser",
"title": "Alexander the Swoose (Half Swan, Half Goose)"
},
{
"artist": "Al Donahue",
"title": "The Wise Old Owl"
},
{
"artist": "Woody Herman",
"title": "Blue Flame"
},
{
"artist": "Washboard Sam",
"title": "She Belongs to The Devil"
},
{
"artist": "Dorival Caymmi",
"title": "O Mar"
},
{
"artist": "Ray Noble",
"title": "By the Light of the Silvery Moon"
},
{
"artist": "Joel & Gaucho",
"title": "Aurora"
},
{
"artist": "Jay McShann",
"title": "Vine Street Blues"
}
]
}
我想在每年删除重复的条目。我试过但是它不起作用：
<?php
$decade = file_get_contents("decade.json");
$decade = json_decode($decade, true);
foreach($decade as $key => $year) {
foreach($year as $k => $item) {
$title = $item["title"];
$artist = $item["artist"];
$i = 0;
foreach($year as $kkk => $it) {
if ($it["title"] = $title) {
unset($decade[$key][$kkk]);
//echo "found";
}
$i = $i + 1;
}
}
}
echo json_encode($decade);
?>
答案 0 :(得分：1)
方法（关于检查'重复'有点过分了）......
检查它是否是重复条目的简单方法是在输出数组上使用 in_array 。我不喜欢它对大型阵列来说会变得昂贵。虽然很容易编码。
如果您使用“密钥”，则可以快速检查数组中是否存在重复条目。
我选择使用'钥匙'......
'songSigniture'包括：
小写标题
然后转换为 SHA1 哈希。
根据数组'$ songSignitures'检查此 songSigniture 。
这不是很多“额外代码”，但不需要它。
测试：PHP 5.3.29; Working code at Eval.in
$outSongs = array();
$outDuplicates = array();
// Avoid 'in_array' scans which are expensive for large arrays... need to benchmark it
// Create a 'signature' of 'year', artist and title as a 'key' so we
// can check it exists in the array quickly.
$songSignitures = array();
foreach($source as $year => $yearSongs) { // songs by year...
foreach ($yearSongs as $songDetails) { // all the songs for one year
$artist = $songDetails['artist'];
$title = $songDetails['title'];
// generate a 'key' that can be checked quickly but is unique.
// make it lettercase insensitive.
$songSig = sha1($year .'|'. strtolower($artist) .'|'. strtolower($title));
if (!isset($songSignitures[$songSig])) { // add to the output...
$songSignitures[$songSig] = true;
$outSongs[$year][] = $songDetails;
}
else { // store duplicates for checking later
$outDuplicates[$year][] = $songDetails;
}
}
}
echo '<pre>';
print_r($outSongs);
echo '</pre>';
echo '<pre>';
print_r($outDuplicates);
echo '</pre>';
/*
echo '<pre>';
print_r($songSignitures);
echo '</pre>';
*/
答案 1 :(得分：0)
您在IF语句中用于字符串之间比较的条件不正确。你应该使用：
（$ it [“title”] === $ title）
而不是：
（$ it [“title”] = $ title）