Solved HashMap being picky?

So I have stumbled upon this irritating 'bug', I'm saying 'bug', because I might have done something wrong, anyways, lets get on to the problem.

I have a HashMap, which stores a string and an integer.
When running this code:

Code:java

for(Entry<String, Integer> entry : myHashMap.entrySet()) {
    if(entry.getKey() == p.getName()) {
        myString = myString.replaceAll("%s", entry.getValue() + "");
    }
}
p.sendMessage(myString);

I get this message: "blah blah blah 100", this 100 is actually %s and being replaced by the entry-s value, which is what I need.

Now if I were to relog, then the %s won't be replaced and I get a message "blah blah blah %s" .

Any help?

 

You don't compare String with ==. That checks if they are the same instance. Use equals as for all objects.

 

ItsOneAndTwo You should use .equals() rather than ==. There is a difference between the two, and the difference is subtle, but very important.

Let's say you have your own class, let's call it Example.class, and all it has is a String that it stores, defined as an argument in the constructor.

== detects if they are the exact same instance
.equals() detects if they have the same values within the class.
In our Example...

Code:java

Example e1 = new Example("a");
Example e2 = e1;
e1 == e2; //returns true
e1.equals(e2); //returns true
 
Example e1 = new Example("b");
Example e2 = new Example("b");
e1 == e2; //returns false
e1.equals(e2); //returns true

Setting e1 equal to e2 makes it the same exact instance, therefore returning true for ==. BUT, in the second example, == returns false, because even though they have the same values, they are two separate instances.
Because they have the same values (the string "b") in the second example, .equals will return true.

 

Thank you, Necrodoom and unon1100, I got that messed up somehow

 

Code:java

for( String key : myHashMap.keySet() )
{
  if( key.equals( p.getName() ) )
    /// do things with myHashMap.get( key );
}

My way of doing it