swift基础1

let myConstant = 42;

var myVariable = 42;
myVariable = 50;

let implicitInteger = 70;
let implicitDouble = 70.0;
let explicitDouble : Double = 70;

var numb : Double;

let label = "The width is";
let width = 94;

let width_a = 94;
let widthLabel : String = String(width_a);

let apples = 3;
let oranges = 5;
let fruitSummary = "I have \(apples + oranges) pieces of fruit";