KOTLIN somo la 18: string na method zinazotumika kwenye list data type.
Katika somo hili tutajifunza method zinazofanya kazi kwenye list data type kwenye Kotlin.
Katika somo hili tutatumia mifano kwenye list yetu hii ['bongoclass', 'facebook', 'google', 'youtube', 'microsoft'].
List properties
Hizi ni sifa ambazo kila list lazima ziwe nazo.
First hii itatuonyesha item ya mwanzo kabisa mwa hiyo list.
fun main() {
val list1 = listOf("bongoclass", "facebook", "google", "youtube", "microsoft")
println(list1.first())
}
Hii itakupa bongoclass
isEmpty hii itupa majibu true kama list haina kitu ama false kama ina kitu.
fun main() {
val list1 = listOf("bongoclass", "facebook", "google", "youtube", "microsoft")
println(list1.isEmpty())
}
Hii itakupa jibu false.
isNotEmpty hii itaangalia kama list haina kitu itatupa jibu true na kama ina kitu itatupa jibu
false.
fun main() {
val list1 = listOf("bongoclass", "facebook", "google", "youtube", "microsoft")
println(list1.isNotEmpty())
}
Hii itakupa jiu true
size hii itaangalia idadi ya item kwenye hiyo list kwa mfano hapo itatupa jibu 5.
fun main() {
val list1 = listOf("bongoclass", "facebook", "google", "youtube", "microsoft")
println(list1.size)
}
Hii itakupa jibu 5
last hii itatuonyesha item ya mwisho.
fun main() {
val list1 = listOf("bongoclass", "facebook", "google", "youtube", "microsoft")
println(list1.last())
}
Hapo itakupa jibu microsoft
reversed hii itapangilia tena list kutoka mwisho kuja mwanzo.
fun main() {
val list1 = listOf("bongoclass", "facebook", "google", "youtube", "microsoft")
println(list1.reversed())
}
single hii itafanya kazi tu kama item kwenye list ni moja, itadisplay item hiyo, kama ni zaidi ya moja haitafanya kazi.
fun main() {
val list1 = listOf("bongoclass", "facebook", "google", "youtube", "microsoft")
println(list1.isNotEmpty())
println(list1.size)
println(list1.last())
println(list1.reversed())
println(list1.singleOrNull())
}
Kuongeza item kwenye list
add() hii hutumika kuongeza item moja mwishoni mwa list.
fun main() {
val list1 = mutableListOf("bongoclass", "facebook", "google", "youtube", "microsoft")
list1.add("github")
println(list1)
}
addAll hii hutumika kuongeza item zaidi ya moja kwenye list.
fun main() {
val list1 = mutableListOf("bongoclass", "facebook", "google", "youtube", "microsoft")
list1.addAll(listOf("github", "instagram", "telegram"))
println(list1)
}
insert hii hutumika kuongeza item kwenye list sehemu unapotaka kwa kutumia index.
fun main() {
val list1 = mutableListOf("bongoclass", "facebook", "google", "youtube", "microsoft")
list1.add(2, "apple")
println(list1)
}
insertAll hii ni sawa na insert ila inaongeza item zaidi ya moja.
fun main() {
val list1 = mutableListOf("bongoclass", "facebook", "google&quo">...
