How to compare two maps by their values

Question

How to compare two maps by their values? I have two maps containing equal values and want to compare them by their values. Here is an example:

    Map a = ne         


        

Answer 1

The result of equals in your example is obviously false because you are comparing the map a with some values in it with an empty map b (probably a copy and paste error). I recommend to use proper variable names (so you can avoid these kinds of errors) and make use of generics, too.

    Map first = new HashMap();
    first.put("f"+"oo", "bar"+"bar");
    first.put("fo"+"o", "bar"+"bar");

    Map second = new HashMap();
    second.put("f"+"oo", "bar"+"bar");
    second.put("fo"+"o", "bar"+"bar");

    System.out.println("equals: " + first.equals(second));

The concatenation of your strings doesn't have any effect because it will be done at compile time.