<?php

//定义数组常量，如何定义？

$Exception=['ClassNotFoundException','DataFormatException','RuntimeException'];

$Error=['LinkageError','ThredDeath'];

$Throwable=Compact('Exception','Error');

define('THROWABLE',$Throwable);

print_r(THROWABLE);

echo THROWABLE['Exception']['2'];

PHP Warning:  Constants may only evaluate to scalar values in arr.php on line 6
PHP Notice:  Use of undefined constant THROWABLE - assumed 'THROWABLE' in arr.php on line 7
PHP Notice:  Use of undefined constant THROWABLE - assumed 'THROWABLE' in arr.php on line 8
PHP Warning:  Illegal string offset 'Exception' in arr.php on line 8
PHP Notice:  Uninitialized string offset: 2 in arr.php on line 8
THROWABLE

请问这样定义数组不可以吗。。。