c# - Replacing a substring consisting of a digit -

i'm newbie programmer sorry in advance if i'm asking too-obvious question.

i program in c#(wpf).

i have few strings built in structure:

string str ="david went location 1 have lunch"; string str2 ="mike has walk mile facing north reach location 2"; 

how can cut "location 1" out in elegant way replace string (that hold restaurant's name, continue example)??

i thought of doing like:

str.replace("location 1", strrestaurantname); 

but should generic(to allow replacement of location x), should using str.indexofto digit's position(it can number between 1 , 20), can't work...

oh, , unfortunately boss doesn't want me use regular expressions, or i'd have now.

thanks in advance.

you use dictionary like:

 dictionary<string, string> restaurants = new dictionary<string, string>();      public form1()     {         initializecomponent();         restaurants.add("location 1", "abc restaurant");         restaurants.add("location 2", "abd restaurant");         restaurants.add("location 3", "abe restaurant");         restaurants.add("location 4", "abf restaurant");         restaurants.add("location 5", "abg restaurant");     }      private void button1_click(object sender, eventargs e)     {       string str ="david went location 1 have lunch";       string str2 ="mike has walk mile facing north reach location 2";          messagebox.show( getrestaurant(str));         // result: david went abc restaurant have lunch          messagebox.show( getrestaurant(str2));         // result: mike has walk mile facing north reach abd restaurant     }      private string getrestaurant(string msg)     {         string restaurantname = "";         foreach (string loc in restaurants.keys)         {             if (msg.contains(loc))             {                 restaurantname = msg.replace(loc, restaurants[loc]);                 break;             }         }         return  string.isnullorempty(restaurantname) ? msg : restaurantname;     } 

and use linq shorten getrestaurant method this:

    private string getrestaurant(string msg)     {         string restaurantname = restaurants.keys.firstordefault<string>(v => msg.contains(v));         return string.isnullorempty(restaurantname) ? msg : msg.replace(restaurantname, restaurants[restaurantname]);     }