PHP:删除另一个字符串中的字符串字符

$string = "This is a string with abc abc abc.";
$replaced_string = str_replace("abc", "", $string);
echo $replaced_string;

This is a string with   .

$string = "This is a string with abc abc abc.";
$position = strpos($string, "abc");
if ($position !== false) {
    $replaced_string = substr_replace($string, "", $position, strlen("abc"));
    echo $replaced_string;
}

This is a string with abc abc.