我一直在使用一個可比較的類來正確運行和比較,但是當我嘗試打印這些值時,它給了我內存地址。我知道這可以通過toString
方法解決,但我不確定如何去做。這裏是我的代碼:用toString返回一個字符串java
import java.io.*;
import java.util.*;
import java.lang.Object;
public class StreetAddress implements Comparable<StreetAddress>
{
protected int num;
protected String stName;
public StreetAddress(int n, String s){
num = n;
stName = s;
}
public int getNum(){
// returns the street number
return num;
}
public String getName(){
// returns the street name
return stName;
}
public int compareTo(StreetAddress street) throws ClassCastException{
// exception prevents crash if an address is not compared to
// another address
int compareName = this.stName.compareTo(street.stName);
int compareNum = this.num - street.num;
if (compareName < 0){
// first address comes after compared address
return compareName;
}
else if (compareName == 0){ // same address name
if (compareNum < 0){
System.out.println(this.num + "" + this.stName + ", " + street.num + "" + street.stName);
return compareName;
}
else{
System.out.println("");
return compareName;
}
}
else{
// first address comes before compared address
return compareName;
}
}
public static void main(String args[])
{
StreetAddress add1 = new StreetAddress(7864, "cartesian road");
StreetAddress add2 = new StreetAddress(5141, "cartesian road");
StreetAddress add3 = new StreetAddress(1664, "n kings street");
StreetAddress add4 = new StreetAddress(9753, "pioneer parkway");
StreetAddress add5 = new StreetAddress(3643, "starry avenue");
add1.compareTo(add2);
add4.compareTo(add1);
add3.compareTo(add3);
add2.compareTo(add5);
}
}
'''''/ /異常可以防止崩潰'沒有它沒有。 – EJP 2013-04-11 01:21:47