Java : Sorting unsorted array in descending order

Question

hi guys

i had an array of objects , i need to know how should i sort my unsorted array in descending order according to the highest value inside objects

i need this using for loops not the easy way.

i had done this but it seems there is a problem

code

student[] temp=new student[s.length];

for (int i=0;i<s.length;i++)
{
    if (s[i].GetGpa() > s[i + 1].GetGpa())
    {
        temp[i] = s[i];
    }
}

how should i do it using for loops

Answer 1

This should get you started. You'll need to create your own Comparator and then call Collections.Sort().

Collections.sort(List<T> list, Comparator<? super T> c)

Answer 2

public class Student implements Comparable { ... }
    Arrays.sort(students);
    List<Object> list = Arrays.asList(students);
    Collections.reverse(list);
    students = list.toArray();

Answer 3

I suggest looking at the Wikipedia article for sorting algorithms. Your code fails because you compare each element only with the next one - but that's not a sorting algorithm at all, because in order to be correctly placed in the first position, an element needs to be bigger than all other elements, not just the next one.

Also, Using a lowercase class name is very much against Java coding standards.

Answer 4

for (int j=0;j<s.length;j++) {
    for (int i=0;i<s.length - 1 - j;i++)
    {
        if (s[i].GetGpa() > s[i + 1].GetGpa())
        {
            student temp = s[i];
            s[i] = s[i+1];
            s[i+1] = temp;
        }
    }
}

Answer 5

for(int i=0;i<s.length;i++)
        {
            for(int j=i+1;j<s.length;j++)
                {
            if(s[j].GetGpa()>s[i].GetGpa())

                    {
                    student[] temp=new student[5];
                    temp[j]=s[j];
                    s[j]=s[i];
                    s[i]=temp[j];   
                    }
        }

        }

here is the answer , thank you very much for helping me :)