我在使用 php foreach 循环遍历数组时遇到困难

Question

i need help fetching values from an array,

Array ( [0] => stdClass Object ( 
[service] => text 
[reference] => 12345678 
[status] => approved 
[sender] => webmaster 
[mobile] => 123456789 
[message] => I need hekp. 
[data] => 
[price] => 3.2500 
[units] => 1 
[length] => 86c/1p 
[send_date] => 2021-05-20 15:42:41 
[date] => 2021-05-20 15:42:41 )  )

what i have done

$response = json_decode($result);
foreach($response as $value){
echo $value['units'];
}

i get an error 500 please kindly guide me i am lost

Answer 1

stdClass Object is telling us you have an object inside your array. so your $response structure looks like this in code:

[
    {
        "service": "text",
        "reference": 12345678
    }
]

try this:

$response = json_decode($result);
foreach($response as $value){
    echo $value->units;
}

in response yo your comment on this answer:

if you wanted to neaten this up you could replace the second reference to $response->data with $values :

$values = $response->data;
foreach($values as $value){
    echo "<table>
    <td>$value->reference</td>
    <td>$value->message</td>
    <td>$value->sender</td>
    <td>$value->mobile</td>
     <td>$value->status</td>
     <td>$value->units</td>
    </table>";
}

I suspect this is what you were going for when you wrote it out, but essentially you were declaring $values and then not using it.... then making a call to the same collection as $values.

Answer 2

Next time enable error_reporting and include any errors and warnings you get.

In this instance the issue is fairly obvious. Your array only contains a single item - and that item is an object. The echo construct expects a string (but can handle an implicit cast from other scalar types). It doesn't know how to output the object. If the object implements the __tostring() method then PHP will call that to get a string to output. But stdClass (the type of object you have here) does not have a _tostring() method.

You also don't state in your question if you are looking for a specific value in the data - ie if you know its name - which is rather critical for how you approach the solution.

That you have a stdclass object suggests that you have loaded it from serialized representation of data such as JSON. If you had converted this input to an array instead of an object (most of the things in PHP which will return stdclass objects can also return associative arrays) you could simply have done this:

function walk_array($in, $depth) 
{
    if ($depth><MAXDEPTH) {
       // because you should never use unbounded recursion
       print "Too deep!\n";
       return;
    }
    foreach ($in as $k=>$item) {
       print str_pad("", $depth, "-") . $k . ":";
       if (is_array($item)) {
           print "\n";
           walk_array($item, $depth+1);
       } else {
           print $item;
       }
    }
}

You can convert an object into an associative array with get_object_vars()