Can you explain the concept of an integer pool and its application?

In Java, the integer pool is a mechanism where Integer objects for values in a certain range (usually from -128 to 127) are cached and reused. This means that when creating an Integer with such a value, the existing object from the pool is returned instead of creating a new one.

This helps save memory and improve performance, as frequently used values do not create multiple identical objects.

Example:

Integer a = 100; // taken from the pool
Integer b = 100; // same object as a
System.out.println(a == b); // true

Integer x = 200; // outside the pool
Integer y = 200; // a new object is created
System.out.println(x == y); // false

The integer pool is useful when working with many numeric objects where values often repeat, such as in collections or auto-boxing.