In programming, control flow refers to the order in which the individual statements, instructions, or function calls of a program are executed or evaluated. Kotlin, like other programming languages, includes several control flow constructs including conditional statements (if, when) and loops (for, while, do-while).
“The function of good software is to make the complex appear to be simple.” – Grady Booch
Basic Control Flow
Let’s start with the basics – the if conditional statement.
If Statement
In Kotlin, ‘if’ can be used as a statement as well as an expression.
fun main() {
val a = 10
val b = 20
if (a > b) {
println("$a is greater than $b")
} else {
println("$b is greater than $a")
}
}
Intermediate Control Flow
Next, let’s take a look at the ‘when’ expression and ‘for’ loop.
When Expression
The ‘when’ expression replaces the switch statement in Kotlin.
fun main() {
val number = 3
when (number) {
1 -> println("One")
2 -> println("Two")
3 -> println("Three")
else -> println("Invalid number")
}
}
For Loop
The ‘for’ loop in Kotlin is used to iterate through anything that provides an iterator.
fun main() {
for (i in 1..5) {
println(i)
}
}
Advanced Control Flow
Lastly, let’s delve into the ‘while’ and ‘do-while’ loops.
While Loop
The ‘while’ loop in Kotlin is used to iteratively execute block of code as long as the condition is true.
fun main() {
var i = 1
while (i <= 5) {
println(i)
i++
}
}
Do-While Loop
The ‘do-while’ loop is similar to the ‘while’ loop except that the condition is evaluated after the execution of block of code.
fun main() {
var i = 1
do {
println(i)
i++
} while (i <= 5)
}
Understanding the control flow is a crucial step in becoming a proficient Kotlin programmer. It allows you to control the execution flow of the program, which can make your programs more efficient and manageable. Remember, mastering a programming language is a journey, so keep practicing and exploring more with Kotlin. You’re well on your way to becoming a Kotlin Pro!
