Explain the mechanism of the string pool in the Java programming language

In Java, the String Pool is a special area in memory where string literals and unique string instances are stored.

When a string is created using a literal, for example:

String s = "hello";

Java checks if such a string already exists in the pool. If it does, it returns a reference to it; if not, it adds a new one.

This helps save memory and speeds up string comparison (the == operator compares references).

If a string is created via a constructor:

String s = new String("hello");

then a new object is created in the heap, not linked to the pool, unless intern() is explicitly called:

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

In this case, s2 will refer to the string from the pool.

Thus, the string pool helps avoid duplication of identical strings in memory and optimizes their handling.