Java: sort a String array, whose strings represent int

Question

I have String[] array like

{\"3\",\"2\",\"4\",\"10\",\"11\",\"6\",\"5\",\"8\",\"9\",\"7\"}

I want to sort it in numerical ord

Answer 1

public class test1 {

public static void main(String[] args) 
{
    String[] str = {"3","2","4","10","11","6","5","8","9","7"};
    int[] a = new int[str.length];
    for(int i=0;i<a.length;i++)
    {
        a[i]=Integer.parseInt(str[i]);
    }
    Arrays.sort(a);
    for(int i=0;i<a.length;i++)
    {
        str[i]=String.valueOf(a[i]);
    }
}

}

Answer 2

U can use sol-1 if it contains only numbers in string format.

Solution-1: -

String []arr = {"3","2","4","10","11","6","5","8","9","7"};
        Set<Integer> set = new TreeSet<Integer>();
        Arrays.sort(arr);
        for(String s:arr){
            System.out.print(s+"  ");
            set.add(Integer.parseInt(s));
        }
        System.out.println(set);
        Integer i = new Integer("4f");
        System.out.println(i);

Solution-2:-

String []arr = {"3","2","4","10","11","6","5","8","9","7","jgj","ek"};
        Set<Integer> intSet = new TreeSet<Integer>();
        Set<String> strSet = new TreeSet<String>();
        Arrays.sort(arr);
        for(String s:arr){
            try {
                int i = Integer.parseInt(s);
                intSet.add(i);
            } catch (NumberFormatException e) {
                strSet.add(s);
            }
        }
        List<String> result = new ArrayList<String>();
        for(int val:intSet){
            result.add(val+"");
        }
        result.addAll(strSet);
        System.out.println(result);
    }

Solution-3:-

Write one CustomComparator class and pass it to the sort() method.

public class CustomComparator implements Comparator<String>{

    @Override
    public int compare(String s1, String s2) {
        Integer i1=null;
        Integer i2=null;
        try {
            i1 = Integer.parseInt(s1);
        } catch (NumberFormatException e) {
        }

        try {
            i2 = Integer.parseInt(s2);
        } catch (NumberFormatException e) {
        }

        if(i1!=null && i2!=null){
            return i1.compareTo(i2);
        }else{
            return s1.compareTo(s2);
        }
    }

}

public static void main(){
String []arr = {"3","2","4","10","11","6","5","8","9","7","jgj","ek"};
Arrays.sort(arr, new CustomComparator());
        for(String s:arr){
            System.out.print(s+"  ");
        }
}