The values in the PHP array cannot be obtained. What should I do?

The values in the PHP array cannot be obtained .. After the form is submitted using POST: var_dump ($ _ POST); the output value of the POST array shows that the values in the values & quot; [1] PHP array cannot be obtained ..
After submitting a form using POST:
Var_dump ($ _ POST );
The output value of the POST array is as follows:
Array (10) {["picName"] => array (2) {[0] => string (33) "p_large_18SQ_6bcc000198902d14.jpg" [1] => string (33) "Records"} ["p_large_18SQ_6bcc000198902d14_jpgtop"] => string (5) "290px" ["p_large_18SQ_6bcc000198902d14_jpgleft"] => string (5) "454px" ["p_large_18SQ_6bcc000198902d14_jpgheight"] => string (3) "236" ["p_large_18SQ_6bcc000198902d14_jpgwidth"] => string (3) "150" ["bytes"] => string (5) "100px" ["p_large_4u3y_64f80006f1_5c40_jpgleft"] => string (5) "500px" ["p_large_4u3y_64f80006f00005c40_jpgheight"] => string (3) "150" ["limit"] => string (3) & quot; 150 & quot; [& quot; num & quot;] = & quot; string (1) & quot; 2 & quot "}

However, when the value in the POST is retrieved, for example, _ POST ["p_large_18SQ_6bcc000198902d14.jpgtop"]
The following error occurs: Notice: Undefined index: p_large_18SQ_6bcc000198902d14.jpgtop.
But Yima is clearly in _ POST. this is a magic horse. ==|||||

------ Solution --------------------
Yes, "." in the submitted variable name will change to "_"