在String数组中对2个字符串进行排序（Java）

Question

I have two arrays one for temperatures and one for the cities.If two temperatures are the same the corresponding cities must be shown with alphabetical sort order.For instance

• 24 Sydney
• 22 Athens
• 22 Auckland
• 20 Barcelona

--->This is the sort code.

public static void sort(String[] x , double[] y) {
    boolean doMore = true;

    while(doMore) {    
        doMore = false;  

        for(int i=0; i< x.length-1; i++) {    
            if(y[i] == y[i+1] && x[i] < x[i+1]) {    
                String temp2 = x[i];
                x[i] = x[i+1];
                x[i+1] = temp2;    
            } else if (y[i] < y[i+1]) {    
                double temp = y[i];    
                y[i] = y[i+1];    
                y[i+1] = temp; 

                String temp2 = x[i];        
                x[i] = x[i+1];    
                x[i+1] = temp2;    
                doMore = true;    
            }//if    
        }//for 2    
    }//while    
}// sort */

The problem is that on the if(y[i] == y[i+1] && x[i] < x[i+1]) i can't just compare 2 stings with the operator > . I can't use any ready sort methods either.

Does anyone know how to sort tho strings alphabetical there?

Answer 1

String is Comparable , so you can use s1.compareTo(s2)

See String.compareTo for details; it returns something negative, 0 or something positive, depending on whether s1 comes before s2 lexicographically, that is to say whether s1 would stand before s2 in a dictionary.

Answer 2

The closest answer to your current implementation is G. Bach's; you should look into his answer for an easy solution.

Thinking a little outside the box...

You current implementation has the potential downside that your arrays could get out of sync in respect to the indexes which would end up having temperatures for the wrong cities. You could try a custom type which encapsulates both fiels and have a list of those. Something like...

public class CityTemperatureInfo implements Comparable<CityTemperatureInfo>
{
    public string cityName;
    public double temperature;

    ...
}

Then your app would use the data as a List<CityTemperatureInfo> . This would ensure the city names and temperatures are always at the same place in the list. And if you make the class comparable, you can implement the int compareTo(CityTemperatureInfo other) method which would allow you to simple call sort on your list.

usually, it is a good idea to keep related data together to avoid potential problems of the data becoming out of sync.