? Java String Pool Memory

? Quick Overview

The String Pool in Java is a special memory area inside the Heap where string literals are stored. It improves memory efficiency by reusing immutable string objects instead of creating duplicate instances.

? Key Concepts

• String literals are stored in the String Pool
• Identical literals point to the same memory reference
• Strings created using new keyword are stored outside the pool
• Strings are immutable
• The intern() method moves strings to the pool

? Syntax / Theory

When a string literal is created, JVM checks the String Pool first. If the value already exists, it reuses the reference. Otherwise, a new string is added to the pool.

? Code Example(s)

// String literals are stored in the String Pool
String s1 = "Java";
String s2 = "Java";

// Comparing references
System.out.println(s1 == s2);

// String created using new keyword is outside the pool
String s1 = "Hello";
String s2 = new String("Hello");

// Reference comparison
System.out.println(s1 == s2);

// intern() moves the string to the String Pool
String s1 = new String("World");
String s2 = s1.intern();

// Now both references point to pool memory
System.out.println(s1 == s2);

? Live Output / Explanation