首先对Array By变量进行排序，然后按降序对其进行排序

Question

Hey guys here is my question. im using JCombobox. if a student have CB grade in the lesson,it should be appear in the jcombobox first , like that CB AA BA BB CC DC DD FD FF if student have DD grade it should be shown like that DD AA BA BB CB CC DC FD FF.

Here all Array members

String[] subset = new String[]{"AA", "BA", "BB", "CB", "CC", "DC", "DD", "FD", "FF"};

if a student have BB grade in the lesson array should be sorted like that BB AA BA BB CB CC DC DD FD FF. these mean array should be sorted by student grade in the first element of array. then it should be sorted by descending order.

i asked sorting arrray because jcombobox work on that. is there a function or method which do that ?

thanks.

Answer 1

How about this:

public static String[] getCustomSortArray(String grade, String[] grades)
{
    int index = -1;
    for(int i = 0; i < grades.length; i++)
    {
        if(grades[i].equals(grade))
        {
            index = i;
            break;
        }
    }

    if(index == -1) return grades;

    String temp = new String[grades.length];
    temp[0] = grades[index];

    int counter = 1;
    for(int i = 0; i < grades.length; i++)
    {
        if(i != index) temp[counter++] = grades[i];
    }
    return temp;
}

I didn't test it, but I think it works.

Answer 2

您始终可以使用Arrays.sort（）根据给定的Comparator对数组中的元素进行排序，在这种情况下，您需要根据自己的需要设计比较器。

Answer 3

for sorting array you can use, it uses compareTo() method of Comparable interface for sorting.

Arrays.sort(array);

For descending sorting you can use Collections.reverseOrder() comparator.

If I understand you right this comparator can work for you.

        Object yourComparator = new Comparator<Comparable<Object>>() {
            @Override
            public int compare(Comparable<Object> c1, Comparable<Object> c2) {
                if(c1.equals(variable)){
                    return 1;
                }
                else if(c2.equals(variable)){
                    return -1;
                }
                else {
                    return c2.compareTo(c1);
                }

            }



        };