array_merge与+的区别

<?php$a = array("a"=>1,"b"=>2,"c"=>3);$b = array("aa"=>1,"22"=>2,"cc"=>3);$data = array_merge($a,$b);print_r($data);$data2 = $a + $b;print_r($data2);?>

结果：

Array(    [a] => 1    [b] => 2    [c] => 3    [aa] => 1    [0] => 2    [cc] => 3)Array(    [a] => 1    [b] => 2    [c] => 3    [aa] => 1    [22] => 2    [cc] => 3)

array_merge：数字键名将会被重新编号！如果你想完全保留原有数组并只想新的数组附加到后面，用+运算符。