Wrapper Classes in Java often seem confusing to beginners, but they are used everywhere — in Collections, Frameworks, type conversions, and even in interview questions.
In this video, I explain Wrapper Classes from scratch with simple examples, covering everything from Boxing, Unboxing, Autoboxing, Auto-Unboxing to all important Integer utility methods you must know for interviews and real-world coding.
💡 What You’ll Learn in This Video:
✔ What are Wrapper Classes in Java?
✔ Why Java is not 100% object-oriented and how Wrapper Classes solve this problem
✔ Need for Wrapper Classes – Collections (List, Map), Type Conversion, Generics
✔ Boxing & Unboxing – Converting primitive types to objects and back
✔ Autoboxing & Auto-unboxing – How Java does conversion automatically
✔ Converting String to int using Integer.parseInt() and valueOf()
✔ intValue(), toString(), compareTo(), max(), min(), sum() methods in Integer class
✔ Understanding Integer.MAX_VALUE and Integer.MIN_VALUE
00:00 : Introduction
00:36 : What’s a Wrapper Class ?
01:34 : Why do we need Wrapper Class ?
01:58 : Boxing
03:21 : Auto-Boxing
04:01 : Unboxing
05:02 : Auto-Unboxing
05:38 : Integer.valueOf()
06:31 : Integer.parseInt()
07:00 : Integer.intValue()
07:13 : Integer.toString()
08:24 : Integer.comapreTo()
10:00 : Integer.max()
10:40 : Integer.min()
10:52 : Integer.sum()
11:07 : Integer.MAX_VALUE
11:36 : Integer.MIN_VALUE
12:14 : Wrapper Classes in Collections
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