java - Incompatible return type of phone number -

how should change code inside of getphonenumber work correctly, idea? should in end +38(050)123-45-67. 38 code of country, phone number 501234567, have put 0 in begin of number 10 numbers here (>0<50)

public string getphonenumber()         {            return string.format("+%d(%2$s)%3$s-%4$s-%5$s", 38,                     string.format("%010d", 501234567).substring(0, 3),                     string.format("%010d", 501234567).substring(3, 6),                     string.format("%010d", 501234567).substring(6, 8),                     string.format("%010d", 501234567).substring(8));          } 

complete code.

public class solution {     public static map<string,string> countries = new hashmap<string,string>();      public static class incomedataadapter implements customer, contact, incomedata     {         incomedata incomedata;          public incomedataadapter(incomedata incomedata)         {             countries.put("ua","ukraine");             countries.put("ru", "russia");             countries.put("ca", "canada");             this.incomedata = incomedata;         }          @override         public string getname()         {             return incomedata.getcontactlastname()+ incomedata.getcontactfirstname();         }          @override         public string getphonenumber()         {            return string.format("+%d(%2$s)%3$s-%4$s-%5$s", 38,                     string.format("%010d", 501234567).substring(0, 3),                     string.format("%010d", 501234567).substring(3, 6),                     string.format("%010d", 501234567).substring(6, 8),                     string.format("%010d", 501234567).substring(8));          }             @override         public string getcompanyname()         {             return incomedata.getcompany();         }          @override         public string getcountryname()         {             return countries.get(incomedata.getcountrycode());         }          @override         public string getcontactfirstname()         {             return "ivan";         }          public incomedata getincomedata()         {             return incomedata;         }          @override         public string getcountrycode()         {             return "ua";         }            @override         public string getcompany()         {             return "javarush ltd.";         }          @override         public string getcontactlastname()         {             return "ivanov";         }          @override         public int getcountryphonecode()         {             return 38;         }     }      public static interface incomedata {         string getcountrycode();                 string getcompany();                     string getcontactfirstname();           string getcontactlastname();             int getcountryphonecode();              void getphonenumber();               }      public static interface customer {         string getcompanyname();                 string getcountryname();            }      public static interface contact {         string getname();                        string getphonenumber();             } } 

both incomedata , contact interfaces have getphonenumber method. 1 declares return type of void while other declares return type of string.

you're trying implement both these interfaces incomedataadapter class. declaring overriden method was

@override public string getphonenumber() { 

it doesn't satisfy contract of incomedata. if declared as

@override public void getphonenumber() { 

it wouldn't satisfy contact interface. basically, can't have methods same definition (name , parameter list) different return types.

change incomedata interface declare getphonenumber method string return type.