Initialize and prepend to a list
The List in Scala is like the Array in that they are a sequence of objects that share the same type. The List collection, however, is immutable. When performing operations on lists, the result will be a new list with a new value. The cons operator (::) prepends an element to a list.
Imagine you wanted to raise the stakes a little when playing Twenty-One by adding a monetary prize for each round. The winner of round one gets $10, the winner of round two gets $15, etc.
In this exercise, you'll create a list to store these prize values for five rounds, then prepend to it to accommodate another round.
แบบฝึกหัดนี้เป็นส่วนหนึ่งของหลักสูตร
Introduction to Scala
คำแนะนำการฝึกหัด
- Initialize a list named
prizeswith an element for each round's prize, where the first through fifth round's prizes are 10, 15, 20, 25, and 30, respectively. - Prepend to
prizesusing the cons (::) operator so a new first round is added, worth $5. Name the new listnewPrizes.
แบบฝึกหัดเชิงโต้ตอบแบบลงมือทำ
ลองทำแบบฝึกหัดนี้โดยเติมโค้ดตัวอย่างนี้ให้สมบูรณ์
// Initialize a list with an element for each round's prize
val ___ = ___
println(prizes)
// Prepend to prizes to add another round and prize
val ___ = ___
println(newPrizes)