Kotlin Newbie To Pro - VARARG, DEFAULT AND NAMED PARAMETERS - Part 18

[@luismarez4792]

first homework i share:
fun alternatingSum(vararg numbers: Int) : Int {
var n: Int = 1
var sum: Int = 0
for(item in numbers) {
sum += (item * n)
n *= -1
}
return sum
}
and thank you for your tutorials they really help me

[@willianrodrigohuber7968]

Thanks for this video, my answer for the homework stay bellow
fun main() {
val sum = alternatingSum(3, 4, 5, 2, 1, 2, 3)
println("The alternating sum is $sum")
}
fun alternatingSum(vararg values: Int): Int {
var sum = 0
for (index in values.indices) {
if (index % 2 == 0) sum += values[index] else sum -= values[index]
}
return sum
}

[@younesscoder]

Thanks again dude
=>This is the solution of the Homework
fun main() {
val sum = alternatingSum(3, 4, 5, 2, 1, 2, 3)
println("The alternating sum is $sum")
}
fun alternatingSum(vararg numbers: Int): Int {
var result = numbers[0]
var o = 0
while(o != (numbers.size - 1)) {
o++
result -= numbers[o]
o++
result += numbers[o]
}
return result
}

[@VijayRaj-pw2px]

fun main() {
// create function that will take a vararg list of numbers and return an alternating sum
val num = alternatingSum(2, 4, 8, 10, 14)
println("The alternating sum is $num")
}
fun alternatingSum(vararg numbers: Int): Int {
var total = 0
for(i in 0 until numbers.size step 2) {
total += numbers[i]
}
for(i in 1 until numbers.size step 2) {
total -= numbers[i]
}
return total
}

[@PB-op3tk]

Hi, i think there is a little mistake in the solution (14:20). In line 14, shouldn't it be: for (i in 0 until list.size), because until does not include the last number, so if you would search for 7 it would return -1
However, nice videos, thanks! 👍

[@PB-op3tk]

Okay, I just saw that someone mentioned the problem in the next video.. so, that applies here, too :)

[@veeecos]

+1

[@aakashkumaryadav6048]

//HomeWork :
fun main() {
val result = alternatingSum(3, 4, 5, 2, 1, 2, 3)
println("The alternating sum is: $result")
}
fun alternatingSum(vararg numbers: Int): Int {
var evenSum = 0
var oddSum = 0
for(i in numbers.indices) {
if(numbers[i]%2 == 0) {
evenSum += numbers[i]
} else {
oddSum += numbers[i]
}
}
return oddSum - evenSum
}
//Thankk you sir

[@swakshatmishra]

fun alternatingSum(vararg numbers: Int): Int {
var sum = numbers[0]
for(i in 1..

[@Macias096]

Is it okay to use, in for loop, the indices function instead of 0 until list.size-1? Looks like this: for (i in list.indices). Program works fine with that.

[@AniobiStanley]

fun alternatingSum(vararg numbers: Int): Int{
var sum = 0
for (i in numbers.indices){
if (i % 2 == 0) sum += numbers[i]
else sum -= numbers[i]
}
return sum
}

[@ekkawutemeelugsana7068]

fun main() {
val sum = alternatingSum(3,4,5,2,1,2,3)
println("The alternating sum is $sum")
}
fun alternatingSum(vararg numbers : Int) : Int {
var result = 0
for((index,item) in numbers.withIndex())
if (index % 2 == 0) result += item
else result -= item
return result
}

[@itamarribeiro8865]

fun alternatingSum(vararg values: Int) {
var result = 0
var sum = true
for (i in values) {
if (sum) result += i
else result -= i
sum = !sum
}
println("The alternating sum is $result")
}

[@opdmin]

fun main() {
val sum = alternatingSum(16,64,47,2,9,18,3,1,74)
println("The alternating sum is $sum")
}
fun alternatingSum(vararg numbers: Int): Int {
var sum = 0
val numberTotal = numbers.size - 1
for(i in 0.. numberTotal) {
if(i%2 != 0) { // odd indexes
sum -= numbers[i] // subtract value
} else { // positive indexes (includes index 0)
sum += numbers[i] // add value
}
}
return sum
}

[@MrSarma1991]

my homework :D
fun alternatingSum(vararg niz: Int):Int
{
var plusminus=0
var rezultat=0
for(i in niz)
{
if (plusminus==0) {
rezultat += i
plusminus = 1
}else {
rezultat -= i
plusminus = 0
}
}
return rezultat
}

[@paulvickers8059]

fun main() {
val sum = alternatingSum(3, 4, 5, 2, 1, 2, 3)
println("The alternating sum is $sum")
}
fun alternatingSum(vararg numbers: Int): Int {
var result = numbers[0]
for (i in 1 until numbers.size) {
if (i % 2 == 0) result += numbers[i] else result -= numbers[i]
}
return result
}

[@alh311]

Homework:
fun alternatingSum(vararg numbers: Int): Int {
var sum = 0
var signModifier = 1
for (number in numbers) {
sum += (signModifier * number)
signModifier *= -1
}
return sum
}

[@pranaydas3320]

fun main() {
val sum = alternatingSum(3, 4, 5, 2, 1, 2, 3, 20,12, 4, 6,7,9,34)
println("The alternating sum is $sum")
}
fun alternatingSum(vararg numbers: Int): Int {
var altSum = 0
for (i in numbers.indices) {
if (i%2 == 0){
altSum += numbers[i]
} else {
altSum += numbers[i] * -1
}
}
return altSum
}

[@PandleHandle]

What does the asterisk in *array do? Are there any other uses for it?

[@PandleHandle]

The * operator is known as the Spread Operator in Kotlin.
When we call a vararg-function, we can pass arguments one-by-one, e.g. asList(1, 2, 3), or, if we already have an array and want to pass its contents to the function, we use the spread operator (prefix the array with *):

[@callmejacrispy]

fun main() {
val sum = altSum(3, 4, 5, 2, 1, 2, 3)
println(sum) // Output should be 0
}
fun altSum(vararg numbers: Int): Int {
var sum = 0
for (i in numbers.indices) {
if (i % 2 == 0) {
sum += numbers[i] // Add numbers at even index positions
} else {
sum -= numbers[i] // Subtract numbers at odd index positions
}
}
return sum
}

[@17thserumano]

fun main() {
sumValue(1, 5)
}
fun sumValue(a:Int, b:Int){
var count = a
var res = 0
while (count

[@soualehmohamedaya6625]

Homework :
fun alternatingSum(vararg numbers: Int) : Int {

var sum = 0
var x = 0


for ( i in numbers ) {
if ( x == 0 ) {
sum += i
x = 1 }
else {
sum -= i
x = 0
}
}
return sum
}
fun main() {

println(alternatingSum(1,2,3,4,5,6))

}

[@TheImaginativeSachin]

interesting

[@jonievillejo6746]

fun main() {
println("For this list [3, 4, 5, 2, 1, 2, 3]")
println("The alternating sum is: ${alternatingSum(3, 4, 5, 2, 1, 2, 3)}")
}
fun alternatingSum(vararg numbers: Int): Int {
var theSum = 0
for ( elementValue in numbers ) {
theSum *= -1
theSum += elementValue
}
return theSum
}

[@shakibhasan858]

a little mistake in line number 14. in the for loop the until keyword don't include the last number. So it should be list.indices

[@LtMewS]

I Used boolean flag variable for this problem
fun alternateSum(vararg numbers: Int): Int{
var flag = true
var sum = 0
for(i in numbers){
if (flag){
sum+=i
flag=false
}
else{
sum-=i
flag=true
}
}
return sum
}

[@lifesurprise9313]

lists and arrays is a very difficult subject, they make ne so confused

[@feanor2718]

I'm Confused:Take a look at the junk i've written:
fun alternatingSum(vararg number: Int): Int {
var value: Int = number[0]
for (i in number.indices) {
if (i != number.size - 1) {
when {
i % 2 == 0 -> value -= number[i + 1]
else -> value += number[i + 1]
}
}
}
return value
}

[@mkc0321]

amazing

[@bogite8734]

fun main() {
val sum = alternatingSum(3, 4, 5, 2, 1, 2, 3)
println("The alternating sum is $sum")
}
fun alternatingSum(vararg numbers:Int):Int {
var current_symbol = "+"
var result = 0
for(n in 0..numbers.size-1) {
val number = numbers[n]
if(current_symbol == "+") {
result += number
current_symbol = "-"
} else if (current_symbol == "-") {
result -= number
current_symbol = "+"
}
}
return result
}

[@Window2015]

fun main(){
var answer=alternatingSum(10,99,67,37,312)
println(answer)
}
fun alternatingSum(vararg number: Int) :Int{
var num2=0
var result:Int
result=number[0]
for (i in 0 until number.size){
if (i

[@MrJonas04]

Who watches this in 2020?

[@SerhiiOr]

I

[@MrJonas04]

@@SerhiiOr ok

[@jessajanson1344]

2021 !!

[@LtMewS]

2023

[@younesscoder]

2023 :^)

[@DeathlabelCSS]

fun main() {
val sum = alternatingSum(3,4,5,2,1,2,3)
println("The alternating sum is $sum")
}
fun alternatingSum(vararg list: Int): Int{
var sum = list[0]
for (i in 1..list.size - 1){
if(i % 2 == 0) // for those that dont know this mathmatical equation its called MOD and essentially it says i divided by 2, but returns the remainer so i MOD 2 would = 0 for even numbers
sum += list[i]
else
sum -= list[i]
}
return sum
}

[@roymustang7031]

//my solution for the homework
fun main(){
var myNumbers=newp(3,4,5,2,1,2,3)
println("The sum is $myNumbers")
}
fun newp(vararg numbers: Int): Int{
var result=numbers[0]
for(i in 1..numbers.size-1){
if(i%2==0){
result+=numbers[i]
}
else{
result-=numbers[i]
}
}
return result
}

[@Kids____Zone]

who watches in 2022?

[@ekafrancium]

fun main() {
val list = listOf(1,2,3,4,5,6,7)
println(list)
println("Search for a number in the $list: ")
val z = readlnOrNull()?.toInt()
if(z!=null) {
println("The index of the $z is: ${indexof(list, z)}")
}
}
fun indexof(list: List, value: Int): Int{
for (i in 0 ..list.size){
if(list[i]==value){
return i
}
}
return -1
}