Splitting String to list of Integers with comma and “-”

Question

Is there a simple way to parse the following String to List of Integers:

String s = \"1,2,5-9,11,12\"

// expected values list: [1,2,5,6,7,8,9,11,12]
List

        

Answer 1

public static void main(String[] args) {
    String str = "1,2,5-9,11,12,19-21";
    String[] val = str.split(",");
    List<Integer> l = new ArrayList<Integer>();
    for (String s : val) {

        if (s.contains("-")) {
            String[] strVal = s.split("-");
            int startVal = Integer.parseInt(strVal[0]);
            int endVal = Integer.parseInt(strVal[1]);
            for (int i = startVal; i <= endVal; i++) {
                l.add(i);
            }
        } else {
            l.add(Integer.parseInt(s));
        }
    }
    for (int j : l) {
        System.out.println(j);
    }
}

O/P : 1 2 5 6 7 8 9 11 12 19 20 21

Answer 2

List<Integer> out=new ArrayList<Integer>();
String numbers[]=s.split(",");
for(String part:numbers){
    if(part.contains("-"){
        int a=Integer.parseInt(part.split("-")[0]);
        int b=Integer.parseInt(part.split("-")[1]);
        while(a<=b){
             out.add(a++);
        }
    }else{
        out.add(Integer.parseInt(part));
    }
}

Answer 3

Magic you are looking at

public static List<Integer> magicallyGetListFromString(String s){
   String[] str=s.split(",");
   List<Integer> result=new ArrayList<Integer>();
   for(String i:str){
       if(i.contains("-")){
           String[] ss=i.split("-");
           int lower= Integer.parseInt(ss[0]);
           int upper= Integer.parseInt(ss[1]);
           for(int j=lower;j<=upper;j++){
               result.add(j);
           }
       }else {
           result.add(Integer.parseInt(i));
       }
   }
    return result;
}

Result:

[1, 2, 5, 6, 7, 8, 9, 11, 12]

Answer 4

This should work:

public class StringMagic
{
    public static void main(String[] args)
    {
        String s = "1,2,5-9,11,12";

        // expected values list: [1,2,5,6,7,8,9,11,12]
        List<Integer> values = magicallyGetListFromString(s);
        for (Integer integer : values)
        {
            System.out.println(integer);
        }
    }

    public static List<Integer> magicallyGetListFromString(String s)
    {
        List<Integer> numberList = new ArrayList<Integer>(); 
        String[] numbers = s.split(",");
        for (String string : numbers)
        {
            if (!string.contains("-"))
            {
                numberList.add(Integer.parseInt(string));
            }
            else
            {
                String[] limits = string.split("-");
                int bottomLimit = Integer.parseInt(limits[0]);
                int upperLimit = Integer.parseInt(limits[1]);
                for(int i = bottomLimit; i <= upperLimit; i++)
                {
                    numberList.add(i);
                }
            }
        }
        return numberList;
    }
}