Recursion 2:Return Keypad Code

public class solution
{
    public static String[] keypad(int n)
    {  
    if(n==0||n==1)
    {
        String ans[]={""};
        return ans;
    }
        int newN=n%10;
        String[] ans=keypad(n/10);
        String helpans=helper(newN);
        String finalans[]=new String[helpans.length()*ans.length];
        int k=0;
        for(int i=0;i<ans.length;i++){
            for(int j=0;j<helpans.length();j++){
            finalans[k]=ans[i]+helpans.charAt(j);
            k++;}
       }
        return finalans;
    }

    private static String helper(int newN){
        if(newN==2)
            return "abc";
        if(newN==3)
            return "def";
        if(newN==4)
            return "ghi";
        if(newN==5)
            return "jkl";
        if(newN==6)
            return "mno";
        if(newN==7)
            return "pqrs";
        if(newN==8)
            return "tuv";
        if(newN==9)
            return "wxyz";
        else
            return "";


    }

}