分类:
2008-11-20 15:50:14
题库内容摘自
1. You are writing a custom dictionary. The custom-dictionary class is named MyDictionary. You need to ensure that the
dictionary is type safe. Which code segment should you use?
A. class MyDictionary : Dictionary
B. class MyDictionary : HashTable
C. class MyDictionary : IDictionary
D. class MyDictionary { ... } Dictionary
= (MyDictionary)t;
Answer: A
2. You are creating a class named Age. You need to ensure that the Age class is written such that collections of Age
objects can be sorted. Which code segment should you use?
A. public class Age { public int Value; public object CompareTo(object obj) { if (obj is Age)
{ Age _age = (Age) obj; return Value.CompareTo(obj); } throw new
ArgumentException("object not an Age"); } }
B. public class Age { public int Value; public object CompareTo(int iValue) { try { return
Value.CompareTo(iValue); } catch { throw new ArgumentException ("object not an
Age"); } } }
C. public class Age : IComparable { public int Value; public int CompareTo(object obj) { if (obj is
Age) { Age _age = (Age) obj; return Value.CompareTo(_age.Value); } throw new
ArgumentException("object not an Age"); } }
D. public class Age : IComparable { public int Value; public int CompareTo(object obj) { try
{ return Value.CompareTo(((Age) obj).Value); } catch { return -1; } } }
Answer: C
3. You are creating a class to compare a specially-formatted string. The default collation comparisons do not apply. You
need to implement the IComparable
A. public class Person : IComparable
B. public class Person : IComparable
C. public class Person : IComparable
D. public class Person : IComparable
Answer: A