REVISION DOC BY RABSON

Question 1

26.What is Null safety and how do we test for it?

Answer 1

Kotlin avoids null pointer exceptions by requiring nullable types to be explicitly declared with ?. Test for null using
?.
?:
!!.

Question 2

25.Demonstrate how you implement an array, and a list, how do they differ.

Answer 2

Array: val arr = arrayOf(1, 2, 3)
List: val list = listOf(1, 2, 3)

Arrays have a fixed size, lists can be mutable (mutableListOf()).

Question 3

23. If/Else Statements:

Answer 3

Used to execute code based on a condition.

if (x > 10) {
println(“Greater than 10”)
} else {
println(“Less than or equal to 10”)
}

Question 4

23.When Statements

Answer 4

Used as a replacement for switch-case, checking multiple conditions.

when (x) {
1 -> println(“One”)
2 -> println(“Two”)
else -> println(“Other”)
}

Question 5

23.While Loops:

Answer 5

Repeats code while a condition is true.

var i = 0
while (i < 5) {
println(i) // Prints 0 to 4
i++
}

Question 5

23.For Loops:

Answer 5

Used to iterate over collections or ranges.

for (i in 1..5) {
println(i) // Prints 1 to 5
}

Question 6

24. Demonstrate how to use when, range, for loop, while loop, repeat loop, demonstrate with examples.