如何从数组数组中的stdClass对象访问变量？

Question

I did a print_r on my array $total and it returned the following:

Array ( ) Array ( ) Array ( ) Array ( ) Array ( [0] => stdClass Object ( 
[generated] => 6 [magnitude] => 3 [log_pk] => 14 [result] => 0.5000 ) )
Array ( ) Array ( )

I need to be able to print out log_pk from within the stdClass Object . I have tried print $total[0]->log_pk but that was unsuccessful. The error was Undefined offset: 0 . Any help is appreciated. Thanks.

Answer 1

Are you doing this within a loop? If so then it looks like the array is empty on most iterations. Try:

if (!empty($total)) print $total[0]->log_pk;

Answer 2

所以这是一个循环，你应该先检查索引0是否存在。

if (isset($total[0])) echo $total[0]->log_pk

Answer 3

var_dump() displays structured information about one or more expressions that includes its type and value. Arrays and objects are explored recursively with values indented to show structure.

var_dump($total)

PHP: var_dump - Manual

Answer 4

it looks like your print_r is inside a loop.

while(true){
    $total = some_function();
    print_r($total);
    if($condition) break;
}
// Here - outside the loop, is not the right place for the print_r();

If you want you print outside the loop, you would change $total = some_function(); to $total[] = some_function(); and then you can do print_r($total[index])