小弟偶初学.一个问题整了半天整不出来.帮忙看看饿....Thangks ..
import java.util.*;
class A implements Comparable{
int i;
A(int i){
this.i=i;
}
public String toString(){
return ""+i;
}
public int hashCode(){
return i;
}
public boolean equals(Object o){
return i==((A)o).i;
}
public int compareTo(Object o){
int m=((A)o).i;
return (m<i ? -1 : (m==i ? 0 : 1));
}
}
class B{
String s;
B(String s){
this.s=s;
} public String toString(){
return s;
}
}public class C{
public static void main(String[] args){
HashMap hm=new HashMap();
hm.put(new A(1),new B("a"));
hm.put(new A(3),new B("c"));
hm.put(new A(2),new B("b"));
System.out.println(hm);
HashMap hm1=new HashMap();
hm1.put(new A(4),new B("d"));
hm1.put(new A(3),new B("g"));
hm1.put(new A(2),new B("h"));
hm.putAll(hm1);
System.out.println(hm);
System.out.println("hm.containsKey(1) "+hm.containsKey(new A(1)));
System.out.println("hm.containsValue(new B(\"a\")) "+hm.containsValue(new B("a"))); //为什么这里输出的值 是 false ?? }
}是不是 B类里也要设置点东西才可以调用 containsValue 方法啊??/
import java.util.*;
class A implements Comparable{
int i;
A(int i){
this.i=i;
}
public String toString(){
return ""+i;
}
public int hashCode(){
return i;
}
public boolean equals(Object o){
return i==((A)o).i;
}
public int compareTo(Object o){
int m=((A)o).i;
return (m<i ? -1 : (m==i ? 0 : 1));
}
}
class B{
String s;
B(String s){
this.s=s;
} public String toString(){
return s;
}
}public class C{
public static void main(String[] args){
HashMap hm=new HashMap();
hm.put(new A(1),new B("a"));
hm.put(new A(3),new B("c"));
hm.put(new A(2),new B("b"));
System.out.println(hm);
HashMap hm1=new HashMap();
hm1.put(new A(4),new B("d"));
hm1.put(new A(3),new B("g"));
hm1.put(new A(2),new B("h"));
hm.putAll(hm1);
System.out.println(hm);
System.out.println("hm.containsKey(1) "+hm.containsKey(new A(1)));
System.out.println("hm.containsValue(new B(\"a\")) "+hm.containsValue(new B("a"))); //为什么这里输出的值 是 false ?? }
}是不是 B类里也要设置点东西才可以调用 containsValue 方法啊??/
解决方案 »
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