In the Java Virtual Machine (JVM), String objects are among the most frequently created types. Mastering how the String Pool works is essential for passing technical interviews and writing memory-efficient, high-performance applications.
In Java, a String is immutable, meaning its state cannot be modified after creation. Once a String object is initialized, the character array holding its data is marked as final. When you perform operations like substring() or concat(), Java does not modify the original string; instead, it creates an entirely new String object in memory.
Why does this matter? Immutability is the cornerstone of the String Pool. Because a String cannot change, Java can safely cache it. If two variables point to the same string literal "Hello", they can share the exact same memory address without the risk that one variable will inadvertently alter the value for the other. This significantly reduces memory overhead. If strings were mutable, this sharing would lead to massive
Understanding the design of the String Pool is a common topic in Java technical interviews. Explain in your own words why the immutability of String objects is a mandatory requirement for the existence of the String Pool, and describe the potential memory consequences if Java allowed String objects to be mutable while still attempting to cache them.