/* 変数の型宣言と型推論 */ var welcomeMessage: String var pi: Double = 3 var piFl: Float = 3 var piInt: Int = 3 var piAuto = 3 pi = 3.14 piFl = 3.14 // piInt = 3.14 // error: cannot assign value of type 'Double' to type 'Int' // piAuto = 3…

/* 変数の宣言 varは変数、letは定数 */ var myVar = 42 myVar = 50 let myConst = 42 // myConst = 50 // error: cannot assign to value: 'myConst' is a 'let' constant print("Hello, world!") print("myVar = \(myVar), myConst = \(myConst)")