isNaN 和 nl2br

isNaN()是JavaScript裡的函式,可判斷非為數字

document.write(isNaN(123));
document.write(isNaN(-3));
document.write(isNaN(0.3));
document.write(isNaN(0));
document.write(isNaN(5/16));
document.write(isNaN("A"));

結果為

false
false
false
false
false
true

至於nl2br()則是PHP的函式,可以把像\n之類的換行字元轉成<br>

<?php
$String="Hello, This is C.C.\nCan you hear me?";
echo nl2br($String);
?>

結果

Hello, This is C.C.
Can you hear me?