This document introduces some basic variable declarations in Swift including let constants for pi and attempts, a var variable for amount, and defines a maxCapacity constant as an Int with an initial value of 100 that is later reassigned to 20. It also declares a price constant as a Double.

6. print("Welcome to Swift !")

8. let maxCapacity: Int = 100
var amount: Int = 10
// 再代入時の動作
maxCapacity = 20
amount = 20
値
初期値

9. let pi = 3.14
let attempts = 1
let price: Double = 100
Double 型
Int 型
Double 型