Arrays, String Memory Internals (String Pool & Immutability) & StringBuilder
Master fixed arrays, multi-dimensional matrices, String immutability, String Constant Pool mechanics, and performance optimization with StringBuilder.
The Java String Constant Pool Architecture
### String Immutability & String Pool
In Java, `String` objects are **immutable**. When you write `String s1 = "Java";`, the string literal is stored inside the **String Constant Pool** in JVM Metaspace/Heap. Multiple variables referencing identical string literals point to the exact same heap memory address!