β #JavaFromZero β Day 49
Building reusable Java code with Custom Generic Classes π§©
β’ <T> acts as a type placeholder
β’ One class β works with many types
β’ Compile-time type safety
β’ Widely used in Collections & frameworks
π Deep dive βnotion.so/Custom-Generic-Claβ¦
#Java
1
2
65
β #JavaFromZero β Day 48
Writing safer & reusable Java code with Generics π§©
β’ Type-safe code (errors at compile time)
β’ No manual casting
β’ Used heavily in Collections & APIs
π Deep dive β notion.so/Day-48-Generics-inβ¦
#Java #LearnEveryDay #CodingJourney
1
2
58
β #JavaFromZero β Day 47
Custom sorting in Java
β’ Comparable β natural order (inside class)
β’ Comparator β custom order (outside class)
β’ Used when sorting objects with Collections.sort()
π Deep dive β notion.so/Day-47-Comparable-β¦
#Java #CodingJourney
1
2
39
β #JavaFromZero β Day 45
Learning the Queue Interface
Process data in the right order.
β’ Queue β FIFO processing
β’ PriorityQueue β highest priority first
β’ Deque β insert/remove from both ends
π Deep dive β notion.so/Day-45-Queue-Interβ¦
#Java #LearnEveryDay #Coding
1
2
37
β #JavaFromZero β Day 44
Understanding the Map Interface πΊοΈ
Store data as key β value pairs.
β’ HashMap β fastest lookup, no order
β’ TreeMap β keys always sorted
β’ Keys are unique, values can repeat
π Deep dive βnotion.so/Day-44-Map-Interfaβ¦
#Java #LearnEveryDay
1
2
27
β #JavaFromZero β Day 43
Understanding the Set Interface π§©
No duplicates β just unique data.
β’ HashSet β fastest, no order
β’ LinkedHashSet β maintains insertion order
β’ TreeSet β sorted elements
π Deep dive β notion.so/Day-43-Set-Interfaβ¦
#Java #LearnEveryDay
1
3
36
β #JavaFromZero β Day 42
Mastering the List Interface π§©
Understanding ArrayList vs LinkedList is key.
β’ List β ordered, allows duplicates
β’ ArrayList β fast access, slow inserts
β’ LinkedList β fast inserts, slow access
π Deep dive β notion.so/Day-42-List-Interfβ¦
#Java
1
3
28
β #JavaFromZero β Day 41
Diving into Java Collections π§Ί
A powerful framework to store & manage groups of objects.
β’ List β ordered, duplicates
β’ Set β unique elements
β’ Map β keyβvalue pairs
β’
π Deep dive β notion.so/Introduction-to-Coβ¦
#Java #LearnEveryDay
3
28
β #JavaFromZero β Day 40
Todayβs topic β UML & Class Design π§©
Model real-world systems before coding.
β’ Identify classes (nouns)
β’ Define methods (verbs)
β’ Map relationships β IS-A, HAS-A
π Deep dive β notion.so/Day-40-UML-Class-Dβ¦
#Java #Design # #LearnEveryDay #OOP
1
4
52
β #JavaFromZero β Day 39
Todayβs topic β Design Patterns Basics π§©
β’ Factory β central place to create objects
β’ Singleton β only ONE instance for the whole app
π Deep dive βnotion.so/Day-39-OOP-Design-β¦
#Java #DesignPatterns #LearnEveryDay
1
3
59
β #JavaFromZero β Day 38
Todayβs topic β Wrapper Classes π
Object versions of primitives.
β’ Autoboxing β int β Integer
β’ Unboxing β Integer β int
β’ Needed for Collections & Generics
π Deep dive β notion.so/Day-38-Wrapper-Claβ¦
#Java #LearnEveryDay
1
2
34
β #JavaFromZero β Day 37
Todayβs topic β Static & Instance Blocks β‘
β’ Static block β runs ONCE when class loads
β’ Instance block β runs before constructor on every object creation
π Deep dive βnotion.so/Day-37-Static-Instβ¦
#Java #LearnEveryDay #OOP
1
2
37
β #JavaFromZero β Day 36
Todayβs topic β Anonymous Classes β‘
Create a class without a name for one-time use.
β’ Perfect for quick method overrides
β’ Great for Runnable, Comparator, listeners
Deep dive β notion.so/Day-36-Anonymous-Cβ¦
#Java #OOP #LearnEveryDay
1
2
38
β #JavaFromZero β Day 35
Todayβs topic β Enums π¨
β’ Replaces fragile strings
β’ Great for roles, statuses, modes
β’ Enums can have fields, constructors & methods
β’ Perfect for APIs & real-world apps
π Deep dive βnotion.so/Day-35-Enums-in-Jaβ¦
#Java #OOP #LearnEveryDay
1
3
27
β #JavaFromZero β Day 34
Todayβs topic β Inner & Nested Classes
β’ Static nested class β no outer object needed
β’ Inner (non-static) class β needs outer instance
β’ Inner can access all outer members
π Deep dive β notion.so/Day-34-Inner-Nesteβ¦
#Java #OOP #LearnEveryDay
1
2
29
β #JavaFromZero β Day 32
Todayβs topic β Object class methods π§©
β’ toString() β readable object info
β’ equals() β logical comparison
β’ hashCode() β used in HashMap/HashSet
π Deep dive β notion.so/Day-32-Object-Clasβ¦
#Java #LearnEveryDay #oops
1
2
23
β #JavaFromZero β Day 31
Todayβs keyword β final π
Use it when things must NOT change.
β’ final variable β value locked
β’ final method β canβt be overridden
β’ final class β canβt be inherited
π Deep dive β notion.so/Day-31-Final-Keywoβ¦
#Java #LearnEveryDay #OOP
1
2
22
β #JavaFromZero β Day 30
Todayβs OOP power tool β Interfaces π
Define what must be done, not how.
β’ 100% abstraction
β’ implements β class follows the contract
β’ Multiple inheritance enabled
π Deep dive β notion.so/Day-30-Interfaces-β¦
#Java #OOP #LearnEveryDay
1
4
38
β #JavaFromZero β Day 29
Todayβs OOP pillar β Abstraction
Hide complexity. Show only essentials.
β’ abstract class β canβt be instantiated
β’ abstract methods β no body, child must override
π Deep dive βnotion.so/Day-29-Abstractionβ¦
#Java #OOP #LearnEveryDay
2
24
β #JavaFromZero β Day 28
Todayβs OOP superpower β Polymorphism
One action β many forms.
β’ Powered by runtime method overriding
β’ Parent reference β child object
β’ JVM chooses method at runtime
π Deep dive β notion.so/Polymorphism-in-Jaβ¦
#Java #LearnEveryDay #OOP
1
3
22