如何在PHP中按字符串处理类

$str = "Hello, World!";
$arr = str_split($str, 1);
print_r($arr);

Array
(
    [0] => H
    [1] => e
    [2] => l
    [3] => l
    [4] => o
    [5] => ,
    [6] => W
    [7] => o
    [8] => r
    [9] => l
    [10] => d
    [11] => !
)

$str = "Hello, World!";
$new_str = str_replace(",", " | ", $str);
echo $new_str;

Hello | World!