刪除JSON對象形式陣列用PHP

Question

我想刪除從JSON數組中的元素用PHP

[{"userid":"20"},{"userid":"17"},{"userid":"18"}] 

我想使這樣說，這

[{"userid":"20"},{"userid":"18"}] 

Answer 1

首先解析JSON串，然後取出元素，然後再次對其進行編碼：

$array = json_decode('[{"userid":"20"},{"userid":"17"},{"userid":"18"}]'); 

foreach ($array as $key=>$element) { 
    if ($element->userid == "17") { 
     unset($array[$key]); 
    } 
} 

$output = json_encode($array); 

Answer 2

如果知道元素索引：

unset($array[1]); // 1 is the index of element. 

如果你不知道的元素索引：

// Deserialize the JSON into associative array. 
$users = json_decode('[{"userid":"20"},{"userid":"17"},{"userid":"18"}]', true); 

// For each user and it's index in array of users. 
foreach ($users as $index => $user) { 
    // If currently iterated user id is equals to 17. 
    if ($user["userid"] == 17) { 
     // Remove it from an array of users. 
     unset($users[$index]); 
    } 
} 

// Echo all elements inside an array of users as JSON. 
echo json_encode(array_values($users));