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import java.util.*;  class KeyMaster {  public int i;  public KeyMaster(int i) { this.i = i; }  public boolean equals(Object o) { return i == ((KeyMaster)o).i; }  public int hashCode() { return i; }  }  public class MapIt {  public static void main(String[] args) {  Set set = new HashSet();  KeyMaster k1 = new KeyMaster(1);  KeyMaster k2 = new KeyMaster(2);  set.add(k1); set.add(k1);  set.add(k2); set.add(k2);  System.out.print(set.size() + “:”);  k2.i = 1;  System.out.print(set.size() + “:”);  set.remove(k1);  System.out.print(set.size() + “:”);  set.remove(k2);  System.out.print(set.size()); }  }  What is the result?() 

  • A、 4:4:2:2
  • B、 4:4:3:2
  • C、 2:2:1:0
  • D、 2:2:0:0
  • E、 2:1:0:0
  • F、 2:2:1:1
  • G、 4:3:2:1

参考答案

更多 “ import java.util.*;  class KeyMaster {  public int i;  public KeyMaster(int i) { this.i = i; }  public boolean equals(Object o) { return i == ((KeyMaster)o).i; }  public int hashCode() { return i; }  }  public class MapIt {  public static void main(String[] args) {  Set set = new HashSet();  KeyMaster k1 = new KeyMaster(1);  KeyMaster k2 = new KeyMaster(2);  set.add(k1); set.add(k1);  set.add(k2); set.add(k2);  System.out.print(set.size() + “:”);  k2.i = 1;  System.out.print(set.size() + “:”);  set.remove(k1);  System.out.print(set.size() + “:”);  set.remove(k2);  System.out.print(set.size()); }  }  What is the result?() A、 4:4:2:2B、 4:4:3:2C、 2:2:1:0D、 2:2:0:0E、 2:1:0:0F、 2:2:1:1G、 4:3:2:1” 相关考题
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