Is lesson me hum seekhenge:

• Variable kya hota hai
• Data Type kya hota hai
• Java ke different data types
• Variable declare aur initialize kaise karte hain

Java me variable ek container hota hai jo data store karta hai.

Example: Age, Name, Salary etc.

Variable ek memory location ka naam hota hai jisme hum data store karte hain.

Example:

Age = 25
Name = Sujit

Java me variable declare karne ka syntax:

dataType variableName = value;

Example:

int age = 25;
String name = "Sujit";

public class VariableExample {

    public static void main(String[] args) {

        int age = 22;
        String name = "Sujit";

        System.out.println(name);
        System.out.println(age);

    }

}

Sujit
22

Data Type batata hai ki variable me kis type ka data store hoga.

Example:

• Number
• Character
• Decimal
• Boolean
• Text

Java me mainly 2 types ke Data Types hote hain.

Data Types
│
├── Primitive
└── Non Primitive

Primitive data types simple data store karte hain.

public class DataTypeExample {

    public static void main(String[] args) {

        int age = 22;
        float price = 99.5f;
        char grade = 'A';
        boolean isJavaFun = true;

        System.out.println(age);
        System.out.println(price);
        System.out.println(grade);
        System.out.println(isJavaFun);

    }

}

22
99.5
A
true

Non primitive data types objects ko represent karte hain.

Examples:

• String
• Array
• Class
• Interface

Example:

public class StringExample {

    public static void main(String[] args) {

        String name = "Sujit";

        System.out.println(name);

    }

}

Sujit

Java me variable name likhte waqt kuch rules follow karne hote hain.

✔ Variable name letter ya underscore se start hona chahiye
✔ Variable name number se start nahi ho sakta
✔ Special characters allowed nahi hote
✔ Java keywords variable name nahi ho sakte

age
studentName
_total
price1

1age
student-name
class

public class MultipleVariables {

    public static void main(String[] args) {

        int age = 22;
        String name = "Sujit";
        double salary = 50000;

        System.out.println("Name: " + name);
        System.out.println("Age: " + age);
        System.out.println("Salary: " + salary);

    }

}

Name: Sujit
Age: 22
Salary: 50000

Variable create karna.

int age;

Variable ko value dena.

age = 25;

int age = 25;

• Variable ek memory container hota hai
• Data type decide karta hai variable me kis type ka data store hoga
• Java me 8 primitive data types hote hain
• String ek non primitive data type hai

1️⃣ Variable kya hota hai?
2️⃣ Data type kya hota hai?
3️⃣ Primitive aur non primitive data type me kya difference hai?
4️⃣ Java me kitne primitive data types hote hain?
5️⃣ Variable naming rules kya hain?

Is lesson me humne seekha:

✔ Variable kya hota hai
✔ Data type kya hota hai
✔ Primitive data types
✔ Non primitive data types
✔ Variable naming rules

Next lesson me hum seekhenge:

• Operators in Java
• Arithmetic Operators
• Relational Operators
• Logical Operators