如何通過JSON陣列搜索在PHP

Question

我有一個JSON陣列

{ 
    "people":[ 
    { 
     "id": "8080", 
     "content": "foo" 
    }, 
    { 
     "id": "8097", 
     "content": "bar" 
    } 
    ] 
} 

如何將搜索8097和獲取內容？

Answer 1

的json_decode功能應該幫助你：

$str = '{ 
    "people":[ 
    { 
     "id": "8080", 
     "content": "foo" 
    }, 
    { 
     "id": "8097", 
     "content": "bar" 
    } 
    ] 
}'; 

$json = json_decode($str); 
foreach($json->people as $item) 
{ 
    if($item->id == "8097") 
    { 
     echo $item->content; 
    } 
} 

Answer 2

json_decode()它，像對待任何其他數組或一個StdClass對象

$arr = json_decode('{ 
    "people":[ 
    { 
     "id": "8080", 
     "content": "foo" 
    }, 
    { 
     "id": "8097", 
     "content": "bar" 
    } 
    ] 
}',true); 

$results = array_filter($arr['people'], function($people) { 
    return $people['id'] == 8097; 
}); 


var_dump($results); 

/* 
array(1) { 
    [1]=> 
    array(2) { 
    ["id"]=> 
    string(4) "8097" 
    ["content"]=> 
    string(3) "bar" 
    } 
} 
*/ 

Answer 3

如果你有一個相當小的數字「人」的對象，那麼以前的答案將適用於你。鑑於你的例子有8000個範圍的ID，我懷疑看每一個ID可能並不理想。因此，這裏是將檢查要少得多的人找到合適的人之前（只要人們在ID的順序）另一種方法：

//start with JSON stored as a string in $jsonStr variable 
// pull sorted array from JSON 
$sortedArray = json_decode($jsonStr, true); 
$target = 8097; //this can be changed to any other ID you need to find 
$targetPerson = findContentByIndex($sortedArray, $target, 0, count($sortedArray)); 
if ($targetPerson == -1) //no match was found 
    echo "No Match Found"; 


function findContentByIndex($sortedArray, $target, $low, $high) { 
    //this is basically a binary search 

    if ($high < low) return -1; //match not found 
    $mid = $low + (($high-$low)/2) 
    if ($sortedArray[$mid]['id'] > $target) 
     //search the first half of the remaining objects 
     return findContentByIndex($sortedArray, $target, $low, $mid - 1); 
    else if ($sortedArray[$mid]['id'] < $target) 
     //search the second half of the remaining objects 
     return findContentByIndex($sortedArray, $target, $mid + 1, $high); 
    else 
     //match found! return it! 
     return $sortedArray[$mid]; 
}