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Android-Kotlin Digest #1

itscoderslife profile image Damodar Shenoy Originally published at itscoderslife.wordpress.com on ・1 min read

Planning to journal updates on my learning in Android and Kotlin development. This would be mostly from an ​ iOS developer’s perspective. I will be writing gist of what I learnt today and anything specific interesting.

To start off below are some things I learnt in Kotlin and differences with Swift.

Some basics of Kotlin:

var of mutable variables

val of immutable variables / constants

Adding variable value in a string "The value of variable is $variable_name"

Suffix ? for variables holding null values

Also has a javascript big arrow => function like syntax:

fun sum(a: Int, b: Int) : Int = a + b

Conditionals: if (obj is String) { … } and not checks if (obj !is String) { … }

I found switch statements most unique till now:


when (obj) {
1 -> "One" // (case)
"Hello" -> "Greeting" // (case)
is Long -> "Long" // (case)
!is String -> "Not a string" // (case)
else -> "Unknown" // (default case)
}

Ranges are specified as 0..end or 0..end+1 or 0..list.lastIndex

Then we have progressions:

for (x in 1..10 step 2) {
print(x)
}
Jumps alternate steps with keyword step and value 2. Here result would be: 13579

for (x in 9 downTo 0 step 3) {
print(x)
}


Jumps three steps but in reverse order with keyword downTo. Here result would be: 9630

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Damodar Shenoy

@itscoderslife

Mobile App Developer. Working as iOS developer with Obj-C / Swift. Learning Android development. Full-stack enthusiast. All things tech. Exploring Machine Learning.

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