SCJP 1.6版考題 139
出自 陳富國維基館
Given a method that must ensure that its parameter is not null:
11. public void someMethod(Object value){
12. //check for null value
...
20. System.out.println(value.getClass());
21. }
What, inserted at line 12, is the appropriate way to handle a null value?
A. assert value == null;
B. assert value != null : "value is null";
C. if (value == null){
throw new AssertionException("value is null");
}
D. if (value == null){
throw new IllegalArgumentException("value is null");
}
解答
Ans: D
解說:
value是公開的方法someMethod中的參數，此參數會由類別外部給予值，類別無法控制此值… 這種性質的參數測試不適合用asserttion(因assertion可以隨時關掉)
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