how to define variable in kotlin

Defining Variables in Kotlin

To define a variable in Kotlin, you can use the val and var keywords. Here's an explanation for each step:

1. Using val Keyword:
2. The val keyword is used to declare a read-only (immutable) variable. Once assigned, its value cannot be changed.
3. Example: kotlin val pi = 3.14

4. This declares a variable pi with the value 3.14.

5. Using var Keyword:

6. The var keyword is used to declare a mutable variable whose value can be changed after it is assigned.
7. Example: kotlin var radius = 5

8. This declares a variable radius with the initial value of 5, which can be changed later in the code.

9. Type Inference:

10. In Kotlin, you can omit the variable's type if it can be inferred from the value assigned to it.
11. Example: kotlin val message = "Hello, World!"

12. Here, the type of message is inferred as String because it is initialized with a string value.

13. Explicitly Specifying Type:

14. You can also explicitly specify the type of the variable when declaring it.
15. Example: kotlin val number: Int = 10

16. This declares a variable number of type Int with the initial value of 10.

17. Nullable Variables:

18. In Kotlin, you can declare variables as nullable by using the ? operator after the type.
19. Example: kotlin var name: String? = null

20. Here, name is a nullable variable of type String that can hold a null value.

21. Lazy Initialization:

22. You can also declare a variable without initializing it immediately by using the lateinit keyword.
23. Example: kotlin lateinit var userName: String

24. This declares a variable userName of type String that will be initialized later in the code.

25. Variable Naming:

26. Variable names in Kotlin can contain letters, digits, and underscores. They cannot start with a digit.
27. Example: kotlin val userAge = 25

These are the various ways to define variables in Kotlin, allowing for flexibility and type safety in your code.