php str_replace用不同的文本更改字符串中的相同文本

Question

这是文字：

$string = "This is my car. 
my car.
Look my car.";

我想在每个句子之前和之后添加文字： 所以我的结果是：

SOME-TEXT This is my car. SOME-TEXT
SOME-TEXT my car. SOME-TEXT
SOME-TEXT Look my car. SOME-TEXT

我这样想：

$string = str_replace("my car", "SOME-TEXT my car SOME-TEXT", $string);

但我得到了结果：

<p>This is SOME-TEXT my car. SOME-TEXT</p> 
<td>SOME-TEXT my car. SOME-TEXT</td>
<h1>Look SOME-TEXT my car. SOME-TEXT<h1>

这不是我想要的!!!

有什么想法吗？！

Answer 1

$string = str_replace("my car.", "my car. SOME-TEXT", $string);

Answer 2

这实现了你想要的：

$string = "This is my car. 
my car.
Look my car.";
define('SOME_TEXT', 'SOME-TEXT');
define('BEG', SOME_TEXT . ' ');
define('END', ' ' . SOME_TEXT);
$result = BEG . str_replace("\n", END . "\n" . BEG, $string). END;