val original = "abc"
// Evolve the value and send to the next chain
original.let {
println("The original String is $it") // "abc"
it.reversed() // evolve it as parameter to send to next let
}.let {
println("The reverse String is $it") // "cba"
it.length // can be evolve to other type
}.let {
println("The length of the String is $it") // 3
}
// Wrong
// Same value is sent in the chain (printed answer is wrong)
original.also {
println("The original String is $it") // "abc"
it.reversed() // even if we evolve it, it is useless
}.also {
println("The reverse String is ${it}") // "abc"
it.length // even if we evolve it, it is useless
}.also {
println("The length of the String is ${it}") // "abc"
}
// Corrected for also (i.e. manipulate as original string
// Same value is sent in the chain
original.also {
println("The original String is $it") // "abc"
}.also {
println("The reverse String is ${it.reversed()}") // "cba"
}.also {
println("The length of the String is ${it.length}") // 3
}
// Normal approach
fun makeDir(path: String): File {
val result = File(path)
result.mkdirs()
return result
}
// Improved approach
fun makeDir(path: String) = path.let{ File(it) }.also{ it.mkdirs() }
// Normal approach
fun createInstance(args: Bundle) : MyFragment {
val fragment = MyFragment()
fragment.arguments = args
return fragment
}
// Improved approach
fun createInstance(args: Bundle)
= MyFragment().apply { arguments = args }
// Normal approach
fun createIntent(intentData: String, intentAction: String): Intent {
val intent = Intent()
intent.action = intentAction
intent.data=Uri.parse(intentData)
return intent
}
// Improved approach, chaining
fun createIntent(intentData: String, intentAction: String) =
Intent().apply { action = intentAction }
.apply { data = Uri.parse(intentData) }