What happens in Java if you try to create a string that already exists in the string pool?

In Java, strings are immutable objects and are stored in the String Pool to save memory.

If you try to create a string that already exists in the String Pool:

• When using literals, for example String s = "hello";, the JVM checks the String Pool and returns a reference to the existing object.
• When creating a string with new String("hello"), a new object is created on the heap, even if such a string exists in the pool.

To explicitly get a string from the pool for an object created with new, you can call the intern() method:

String s1 = "hello";
String s2 = new String("hello");
String s3 = s2.intern();

System.out.println(s1 == s3); // true
System.out.println(s1 == s2); // false

Thus, if the string already exists in the pool, intern() will return a reference to it, avoiding duplication.