How to decrypt JavaScript like this

I want to know how to decrypt JavaScript like this:

var 0x5377= ["\x48\x65\x6C\x6C\x6F\x20\x57\x6F\x72\x6C\x64\ x21"];var a=_0x5377 [0]; function MsgBox(_0x82a8x3)(alert(_0x82a8x3); }; MsgBox(a);