01-swift Basic Syntax

First, Swift basic operation

1. Import Frame

   OC is #import <UIKit/UIKit.h> Swift is import UIKit

2. Swift definition Identifiers: Constants or variables must be specified

VAR (variable)/let (constant) identifier name: type of identifier = initialization value

var a: Int = ten;   a = ; B = 3.11 wrong wording (type not correct)

let B: Double = 3.14;

3. The statement can not follow after the end;

Premise: A row has only one statement, if there are multiple statements in a row, you need to use; split

4. Print Content

Print (a)

Print ("Hello World")

Second, the use of constants and variables note points:

1. In the development of the first use of constants, only when the need to modify, when modified to Var

2. Constant essence: The saved memory address can not be modified, but can get the object through the memory address, and then modify the properties inside the object

Let View:uiview = UIView ()

view = UIView () error notation

View.backgroundcolor = Uicolor.redcolor ()

3. Create an Object

1. Create UIView object and make frame

Let view: UIView = UIView(frame: cgrect(x: 0, y: 0, Width: , Height:) )

2. Set properties of the UIView

View . BackgroundColor = uicolor. Bluecolor ()

//3. To add child controls inside a view object

3.1. Creating child controls

Enumeration used in //Swift : 1. type of enumeration . Specific type 2: Type of specific

let btn: UIButton = UIButton(type:. Contactadd)

3.2. setting The location of the BTN

btn. Center = cgpoint(x: y:-)

3.3. adds a child control to the in View

View . Addsubview(btn)

Third, the data type

// Type deduction

var a:int = 30

var a =

// You can view the type of an identifier by : Option + left mouse button

Let B = 3.14

01-swift Basic Syntax