String immutability and why it exists, the string pool and interning, the == vs .equals() trap, what the compiler does with + in loops (O(n^2) garbage), StringBuilder's internal char[] resizing, and the full String API — every gotcha documented.
// Lessons
- 01soon
String Immutability — Why Strings Cannot Change (and Why That's Good)
- 02soon
The String Pool — Interning, Literals vs new String()
- 03soon
== vs .equals() — The Classic Mistake and Why It Happens
- 04soon
String Concatenation — What the Compiler Does With +
- 05soon
StringBuilder Internals — char[] Resizing and the Amortised Cost
- 06soon
String API Deep Dive — substring(), intern(), format() and the Gotchas