[英]php unable to update specific array value
I am trying to compare two arrays and update specific array values based on conditions.我正在尝试比较两个数组并根据条件更新特定的数组值。
Getting attendance array of absent students:获取缺席学生的出勤数组:
$array1 =
array(
array("student_id" => "2",
"date" => "2016-04-24"),
array("student_id" => "6",
"date" => "2016-04-24"));
$attendance = json_decode(json_encode($array1));
Getting student list array of all students:获取所有学生的学生列表数组:
$array2 =
array(
array("student_id" => "1",
"Reason" => "",
"date" => "2016-04-24"),
array("student_id" => "2",
"Reason" => "",
"date" => "2016-04-24"),
array("student_id" => "3",
"Reason" => "",
"date" => "2016-04-24"),
array("student_id" => "6",
"Reason" => "1",
"date" => "2016-04-24"));
$students = json_decode(json_encode($array2));
Taking out only student IDs of absent students:只取出缺席学生的学生证:
foreach($attendance as $att)
{ $atts[] = $att->student_id;}
Here I am trying to find out if any of the students ID in student array matches with ID in absent array.在这里,我试图找出学生数组中的任何学生 ID 是否与缺失数组中的 ID 匹配。 If ID is present then I will update the Reason as "1".
如果存在 ID,那么我会将原因更新为“1”。 Else will make the reason as 0
否则会使原因为 0
for ($i = 1; $i <= count($students); $i++) {
if(in_array($atts[$i],$students))
{
$students->Reason='1';
}
else
{
$students->Reason='0';
}
}
echo '<pre>',print_r($students,1),'</pre>';
Here I am unable to update student array with "reason" values.在这里,我无法使用“原因”值更新学生数组。
If you just want to compare student_id
from array1
with student_id
from array2
, and set Reason
in array2
if they correspond to each other, use this :如果您只想将
array1
中的student_id
与array2
student_id
进行比较,如果它们彼此对应,则在array2
设置Reason
,请使用以下命令:
foreach ($array1 as $key1 => $value1) {
foreach ($array2 as $key2 => $value2) {
if ($value1['student_id'] == $value2['student_id']) {
$array2[$key2]['Reason'] = 1;
} else if ($array2[$key2]['Reason'] != 1) {
$array2[$key2]['Reason'] = 0;
}
}
}
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