nullp

来自「C实现的MUD,对大家基本入门网络游戏很有帮助!」· 代码 · 共 28 行

     nnnnuuuullllllllpppp((((3333))))               MMMMuuuuddddOOOOSSSS ((((5555 SSSSeeeepppp 1111999999994444))))                nnnnuuuullllllllpppp((((3333))))

     NNNNAAAAMMMMEEEE
          nullp() - determine whether or not a given variable is null.

     SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
          int nullp( mixed arg );

     DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
          Return 1 if `arg' is null.  'arg' will be null in the
          following cases:

          1.   it has not yet been initialized.

          2.   it points to a destructed object.

          3.   it is a function (formal) parameter that corresponds to
               a missing actual argument.

     SSSSEEEEEEEE AAAALLLLSSSSOOOO
          mapp(3), stringp(3), pointerp(3), objectp(3), intp(3),
          bufferp(3), floatp(3), functionp(3), undefinedp(3),
          errorp(3)

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