Object creation of string

Question

Hello
Please tell me what is the difference between these two object creation of string.
String str = new String("Hello");.
String str="Hello";
Thanks.

Answer 1

RGEO wrote:
hello,
Is the string pool is part of a heap? Huh? I suppose yes, you could regard the String pool as part of the heap... but (I guess) that interned String objects would be placed directly into the permanent generation, which is not garbage collected... and therefore I don't really think of the permanent generation as part of the heap (except when tuning heap allocations)... but I think I'm talking over your noob head here, yes... and so to the noob-stuff.
If you get bored you might like to scan (for now) http://java.sun.com/javase/technologies/hotspot/gc/gc_tuning_6.html#generations ... and come back to it in a couple of years time (when every second word isn't new and baffling to you;-)
jvm what will do when he encounter the following code,
String s1 = new String ("hello");The VM will:
1. Create a new String object, and then
2. copy the characters 'h','e','l','l','o' from the interned String "hello" to the new String,
3. and then assign a reference to the new String to variable s1.
Note that the result is subtley different from String s1 = "hello", which just does step 3... it assigns a reference to the existing interned String object "hello" to the variable s1... it does not create and "populate" a new String object.
Try this just for fun... what is the output of the following program? Why?
package forums;
public class StringEquals
  public static void main(String[] args) {
    try {
      String a = "Hello";
      String b = "Hello";
      System.out.println("a==b is "+(a==b));
      String c = new String("Hello");
      System.out.println("a==c is "+(a==c));
    } catch (Exception e) {
      e.printStackTrace();
}Now, what's the correct way to evaluate equality of String objects in Java?
HTH. Cheers. Keith.