php中用加号与用array_merge合并数组的区别深入分析

<?php
$r = array(1,2,3,4,5,6);
$e = array(7,8,9,10);
?>

<?php
print_r($r+e); // 输出<span style="font-family: Simsun;font-size:16px; ">Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 [5] => 6 ) </span>
print "<br />";
print_r(array_merge($r,$e)); // 输出<span style="font-family: Simsun;font-size:16px; ">Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 [5] => 6 [6] => 7 [7] => 8 [8] => 9 )</span>
?>

<?php
$r = array('r'=>1,2,3,4,5,6);
$e = array(<span style="background-color: rgb(245, 250, 255); ">'r'=></span>7,8,9,10);
?>

<?php
print_r($r+e); // 输出Array ( [r] => 1 [0] => 2 [1] => 3 [2] => 4 [3] => 5 [4] => 6 )
print "<br />";
print_r(array_merge($r,$e)); // 输出Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 [5] => 6 [6] => 7 [7] => 8 [8] => 9 )
?>