PHP foreach array return 正则式的问题

Question

$a1 = '/\{[A-Z]*\}/';

$a2 = array(
'{DOMEA} = 'AAAAAA';
'{DOMEB} = 'BBBBBBB';
)

$a3 = return('
    <h1>title</h1>
    {DOMEA}
    <hr>
    {DOMEB}
');
$b1 = preg_replace($a1,$a2,$a3);

怎么才实现$a2自动匹配$a3里对应的内容呢？
满脑子全是浆糊，实在想不出来，用foreach试了半天了也没弄出来，不知那位路过的PHP大大能给解解……

Answer 1

<?php 
//http://3v4l.org/SHdjA
$a1 = '/\{[A-Z]*\}/';
$a2 = array(
'{DOMEA}'=>'AAAAAA',
'{DOMEB}'=>'BBBBBBB'
);
$a3 = '
    <h1>title</h1>
    {DOMEA}
    <hr>
    {DOMEB}
';
echo preg_replace_callback($a1, function($matches) use($a2) {
    return $a2[$matches[0]];
}, $a3);
?>

Answer 2

http://3v4l.org/KudfG

因为这根本不是什么正则，只是最普通的str_replace罢了……

php$a2 = array(
'{DOMEA}' => 'AAAAAA',
'{DOMEB}' => 'BBBBBBB',
);

$a3 = '


<h1>title</h1>


    {DOMEA}
    <hr>
    {DOMEB}
';

echo str_replace(array_keys($a2), array_values($a2), $a3);

Answer 3

php
$a2 = array(
'{DOMEA}' => 'AAAAAA',
'{DOMEB}' => 'BBBBBBB',
);

$a3 = '


<h1>title</h1>


    {DOMEA}
    <hr>
    {DOMEB}
';
echo strtr($a3,$a2);