dynamic array name with values - php

Question

i have arrays as box1 box2 etc...i am trying to find the common elements/values between any 2 random arrays...but i keep getting error that target1 and target2 are not arrays below is my code:-
$box1=array("1","2","3","4","7","9");
$box2=array("11","2","34","4","72","9");
$box3=array("13","42","3","64","7","89");
$box4=array("71","24","38","43","7","19");
$box5=array("1","52","37","94","7","79");
$nos1=rand(1,5);
$nos2=rand(1,5);
$target1="$box".$nos1;
$target1="$box".$nos2;
$common=array();
$common=array_intersect($target1,$target2);

Answer 1

You are assigning random box to target in wrong way. Use the code below:
$box1=array("1","2","3","4","7","9");
$box2=array("11","2","34","4","72","9");
$box3=array("13","42","3","64","7","89");
$box4=array("71","24","38","43","7","19");
$box5=array("1","52","37","94","7","79");
$nos1=rand(1,5);
$nos2=rand(1,5);
$target1=${"box".$nos1};
$target2=${"box".$nos2};
$common=array();
$common=array_intersect($target1,$target2);

Answer 2

Adding to #KamalPaliwal 's answer:
Another way to accomplish/write this with variable variables:
<?php
$box1=array("1","2","3","4","7","9");
$box2=array("11","2","34","4","72","9");
$box3=array("13","42","3","64","7","89");
$box4=array("71","24","38","43","7","19");
$box5=array("1","52","37","94","7","79");
$varname1="box".rand(1,5);
$varname2="box".rand(1,5);
$target1 = $$varname1;
$target2 = $$varname2;
$common=array();
$common=array_intersect($target1,$target2);