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。