Call HashMap Value from Another Method-CodePudding

I'm trying to call the values of the hashmap from another method. I need the values 1, "Twin", 200, 200 to be printed instead of "YES" when TW has been called in ref. However keep in mind I have to leave setupMuseum as private. I've tried different approaches but each time ended up with an error.

  private void setupMuseum() {
        HashMap<String, MUSEUM>Museum= new HashMap<String, MUSEUM>();
        
        Museum.put("TW", new MUSEUM(1, "Twin", 200, 200)); 
    }

public String getMuseumDetails(String ref) {
        if ("TW".equals(ref) ){
            System.out.println("YES");
            
            
        }else
            return "!";
            
        return "\nNo such thing";
    }

CodePudding user response：

Your setupMuseum() method is useless as is. It creates a Map that is not even returned and which is also not an instance variable. You need to return the created Map and then you can print whatever is in there:

private Map<String, MUSEUM> setupMuseum() {
    HashMap<String, MUSEUM> Museum = new HashMap<String, MUSEUM>();
    Museum.put("TW", new MUSEUM(1, "Twin", 200, 200)); 

    return Museum;
}

Then in your getMuseumDetails() method, you need to call setupMuseum() and print the values:

public String getMuseumDetails(String ref) {
    if ("TW".equals(ref) ){
        HashMap<String, MUSEUM> museum = getMuseumDetails();
        System.out.println(museum.get("TW"));
    } else {
        return "!";
    }
    
    return "\nNo such thing";  // This is unreachable
}

This is assuming that both methods are in the same file, so that setupMuseum() can be reached within getMuseumDetails(). This also assumes that your MUSEUM class has an appropriate toString() implementation that actually includes all its properties.

As side notes please keep the following in mind:

Usually, variables in Java follow snakeCase, so you should name Museum as museum.
Java classes should not have their name as uppercase, so you should name MUSEUM as Museum.
You should strive to use Java interfaces instead of concrete implementations. This means that you should use Map<String, MUSEUM> Museum = new HashMap<String, MUSEUM>(); instead of HashMap<String, MUSEUM> Museum = new HashMap<String, MUSEUM>(); so that you declare the variable as a Map (the interface) instead of as a HashMap (the concrete implementation).