PHP格式化、分割、合成字符串

<?php    $num=1868.967777;    echo number_format($num),"<br>";    echo number_format($num,2),"<br>";    echo number_format($num,2,'.','.'),"<br>";?>

1,8691,868.97//逗号1.868.97//点

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<?php    $num="@aaaaa@bbbbb@ccccc@ddddd@eeeee@ffffff";    $str_arr=explode("@", $num);    print_r($str_arr)?>

Array ( [0] => [1] => aaaaa [2] => bbbbb [3] => ccccc [4] => ddddd [5] => eeeee [6] => ffffff ) 

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<?php    $num="@aaaaa@bbbbb@ccccc@ddddd@eeeee@ffffff";    $str_arr=explode("@", $num);    $str_drr=implode("@", $str_arr);    print_r($str_drr)?>

@aaaaa@bbbbb@ccccc@ddddd@eeeee@ffffff