📌 Basic Syntax in Kotlin

Kotlin has a clean and concise syntax, making it easier to read and write. Let's go through some of the basic concepts.

✅ 1. Hello World Program

kotlin
fun () {    println("Hello, World!")}

• fun → Declares a function.

• main() → Entry point of the Kotlin program.

• println() → Prints output with a newline.

✅ 2. Variables and Data Types

Variables in Kotlin

• val → Immutable (read-only) variable. Like final in Java.

• var → Mutable variable.

kotlin
val name: String = "John"  // Immutablevar age: Int = 25          // Mutableprintln("Name: $name, Age: val city = "New York"  // Inferred as Stringvar price = 199.99     // Inferred as Double

✅ 3. Data Types

Common data types in Kotlin:

• Int → Integer (e.g., 10, -20)

• Double → Floating-point number (e.g., 10.5, 99.99)

• Char → Single character (e.g., 'A', 'B')

• String → Text (e.g., "Hello")

• Boolean → True or False

• Array → Collection of items

• List → Ordered collection

✅ 4. Conditional Statements

If-Else

kotlin
val num = 10if (num > 0) {    println("Positive number")} else {    println("Negative number")}

If-Else as Expression

kotlin
val a = 15val b = 10val max = if (a > b) a else bprintln("Max: $max")

✅ 5. When Statement (Switch Equivalent)

kotlin
val dayName = when (day) {    1 -> "Monday"    2 -> "Tuesday"    3 -> "Wednesday"    else -> "Invalid Day"}println(dayName)

✅ 6. Loops

For Loop

kotlin
for (i in 1..5) {    println(i)  // Output: 1 to 5}for (i in 1 until 5) {    println(i)  // Output: 1 to 4}val numbers = arrayOf(10, 20, 30)for (num in numbers) {    println(num)}

While Loop

kotlin
var i = 1while (i <= 5) {    println(i)    i++}

✅ 7. Functions

kotlin
fun (a: Int, b: fun (a: Int, b: var name: String? = nullprintln(name?.length)  // Safe call operator

• ?. → Safe call operator to avoid NullPointerException.

• !! → Non-null assertion operator (throws exception if null).

✅ 9. Classes and Objects

kotlin
class Person(val name: String, var age: Int) {    fun () {        println("Hello, my name is $name and I am $age years old.")    }}val person = Person("Alice", 30)person.greet()

✅ 10. Conclusion

• Kotlin has a clear and expressive syntax.

• Variables can be mutable (var) or immutable (val).

• Control flow is managed using if-else, when, for, and while.

• Functions are simple and support concise expressions.

• Null safety is a core feature.