从此php数组中检索单个值

Question

I have this php array $result2 that looks like this.

[
    (int) 0 => object(stdClass) {
        id => (int) 1
        username => 'asd'
        password => '123'
        fullname => 'asd'
        email_addr => 'asd@gmail.com'
    }
]

From $result2 , I want to have a $json_result that looks like this;

[{"email_addr":"asd@gmail.com"}]

I tried $emailAddress[] = ['email_addr' => $result2['email_addr'] ]; echo json_encode($emailAddress); $emailAddress[] = ['email_addr' => $result2['email_addr'] ]; echo json_encode($emailAddress);

However, the error I get is this;

Notice (8): Undefined index: email_addr [APP/Controller\\DeptUsersController.php, line 126]

The output is like this which is wrong;

[{"email_addr":null}]

What is the correct way?

Answer 1

Read carefully (int) 0 => object(stdClass) It's an object, and this object is an element with index 0 of an array. So:

$emailAddress[] = ['email_addr' => $result2[0]->email_addr ];

Answer 2

如果使用$result2['email_addr']应该使用此$result2->email_addr方法，则该对象将无法显示值

Answer 3

You have an object of type stdClass so you can't access directly to the field email_addr . Try this code:

$mObject = new stdClass();
$mObject = $result2[0];
$emailAddress[] = ['email_addr' => $mObject->email_addr ];
echo json_encode($emailAddress);

This should fix your error

Answer 4

尝试这个：

$emailAddress[] = ['email_addr' => $result2[0]->email_addr ];

Answer 5

You can use array_intersect_key :

$wanted = ["email_addr"=>""];
$data = [
    "id" => 1,
    "username" => 'asd',
    "password" => '123',
    "fullname" => 'asd',
    "email_addr" => 'asd@gmail.com',
];
$result = array_intersect_key($wanted, $data);
var_dump($result);

It useful when you need one or more key to find. It more saving time