When to use the "as" keyword and when to use () casting? [duplicate]

This question already has answers here: Closed 12 years ago.

Possible Duplicate:

Direct casting vs 'as' operator?

as doesn't throw an exception, but开发者_运维技巧 wouldn't it result in a NullPointerException later? doesn't it make it harder to debug?

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after using the as, you should always check for null.