java - i have four string values from method. how to combine strings? -

so value of these string method, , need combine them file address, can't combine string did on file_path_string. tried use concat method, doesn't work too. file_path_string equal first string ,which world_path in case

public static final string world_path = "the world/"; public static string continents_name=""; public static string country_name=""; public static string file_type="";  public static string file_path_string = world_path + continents_name + country_name + file_type; public static file file_path = new file(file_path_string); 

it should work like, when click on map, method return name of region me,and wills store them in static string. tried debug. of strings have value , correct. file_path_string equal first string put in there. after run program, continents_name = asia country_name should equal continents_name because that's how set file address file_path = .png method load map

i curious, how "have 4 string values method" - can enlighten on that? because if this:

getstrings(world_path, continents_name, country_name, file_type); 

then that's problem - function getstrings() can't modify strings passed in.

i making wild guesses of course, since haven't given enough information.

can like:

string path = getworldpath() + getcontinent() + getcountry() + getfiletype(); 

that is, implement 4 separate methods 4 separate parts of path?

otherwise have define type can return 4 strings @ same time, or return them in container array:

void test() {     string[] pathparts = getstrings();     file_path_string = pathparts[0] + pathparts[1] + pathparts[2] + pathparts[3]; }  string[] getstrings() {     string[] ret = new string[4];     ret[0] = "the world";     ret[1] = "south america";     ret[2] = "chile";     ret[3] = ".txt";     return ret; } 

of course, if going concatenate strings, in getstrings() function.