资料来源 : Free On-Line Dictionary of Computing

precedence lossage
     
        /pre's*-dens los'*j/ A {C} coding error in an expression due
        to unintended grouping of arithmetic or logical operators.
        Used especially of certain common coding errors in {C} due to
        the nonintuitively low precedence levels of "&", "|", "^",
        "<<" and ">>".  For example, the following C expression,
        intended to test the least significant bit of x,
     
        	x & 1 == 0
     
        is parsed as
     
        	x & (1 == 0)
     
        which the compiler would probably evaluate at compile-time to
     
        	(x & 0)
     
        and then to 0.
     
        Precedence lossage can always be avoided by suitable use of
        parentheses.  For this reason, some {C} programmers
        deliberately ignore the language's precedence hierarchy and
        parenthesise defensively.  {Lisp} fans enjoy pointing out that
        this can't happen in *their* favourite language, which eschews
        precedence entirely, requiring one to use explicit parentheses
        everywhere.
     
        Other sources of {bug}s include {aliasing bug}, {memory leak},
        {memory smash}, {smash the stack}, {fandango on core},
        {overrun screw}.
     
        [{Jargon File}]
     
        (1994-12-16)