在javascript中动态更改if语句中的条件

Question

此代码是动态更改条件的，但是，此语句是由chrome识别和解释但不是fx，如何解决问题？感谢

if a % 2 == 0 
  var condition = b == c  || b == d;
else 
  var condition = b == e  || b == f ;

if (condition)
  ......

Answer 1

var condition = (a % 2 == 0) ? (b == c  || b == d) : (b == e  || b == f);

Answer 2

像这样写：

var condition;
if (a % 2 == 0)
    condition = b == c  || b == d;
else 
    condition = b == e  || b == f ;

if (condition)
   ......