数组
- Arrays
1、一个数组只能存储特定类型的数据；
2、所存储的数据不一定是一个类的对象，可以是基础数据类型；
var array = ["A","B","C"] //["A", "B", "C"] var array2:[String] = ["A","B","C"] //["A", "B", "C"] var array3:Array<String> = ["A","B","C"] //["A", "B", "C"] array[0] = "AA" //"AA" array //["AA", "B", "C"] var array4 = [Int]() //[] var array5 = Array<String>() //[] var array6:[Int] = [] //[] array = [String]() //清空数组 array array6 = [Int](repeatElement(0, count: 10)) //[0, 0, 0, 0, 0, 0, 0, 0, 0, 0] var array7 = [2,3,4] var array8 = array6 + array7 //两个数组合并 [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 4]
- 数组基本操作
var array = ["A","B","C"] array.count //3 array.isEmpty //false array.append("#") //["A", "B", "C", "#"] array += ["D","E"] //["A", "B", "C", "#", "D", "E"] array.insert("hello", at: 0) //在数组位置上插入 ["hello", "A", "B", "C", "#", "D", "E"] array.remove(at: 0) //"hello" 删除的元素 array.removeLast() //"E" 删除最后一个元素 array[0] = "AA" array //["AA", "B", "C", "#", "D"] array[2...4] = ["CC","DD","EE"] //批量修改,数组赋给数组 array //["AA", "B", "CC", "DD", "EE"] //遍历数组-1 for index in 0..<array.count { print(array[index]) } //遍历数组-2 for item in array { print(item) }
字典
- 字典初始化
1、字典存储的数据是键和值的数据对
2、所存储的数据中，键和值可以是任意数据类型
3、一个字典只能存储固定一种键和值的数据类型搭配
//隐式声明 var dict = [1:"a",2:"b",3:"c"] var site = ["search":"google","web":"mooc"] //显式声明 var dict2:Dictionary<Int,String> = [1:"a",2:"b",3:"c"] var site2:Dictionary<String,String> = ["search":"google","web":"mooc"] var dict3 = Dictionary<Int,String>() //声明一个空字典 dict = Dictionary<Int,String>() //清空字典 dict = [:] //清空字典
- 字典基本操作
var dict = [1:"a",2:"b",3:"c"] var site = ["search":"google","web":"mooc"] dict.count //返回数据对数 dict.isEmpty //是否空 //访问键值 dict[1] //"a" site["search"] //"google" dict[4] //nil dict[0] = "0" //"0" "seo:"+site["search"]! //"seo:google" site.updateValue("imaginecode", forKey: "web") site //["web": "imaginecode", "search": "google"] //遍历key,value for (key,value) in site { print("\(key): \(value)") } //遍历key for key in site.keys{ print(key) } //遍历val for val in site.values{ print(val) } Array(site.keys) //强制类型转换 ["web", "search"]
- 数组与字典在App中的应用
1、列表
示例: UIKit
import UIKit let colors = [ "blue":(red:93,green:138,blue:168), "sweet":(red:254,green:111,blue:94), "yellow":(red:255,green:239,blue:0), "orange":(red:255,green:140,blue:0), "violet":(red:143,green:0,blue:255), "fern":(red:113,green:188,blue:120), "gamboge":(red:228,green:155,blue:15), "cerise":(red:244,green:0,blue:161), "icterine":(red:252,green:247,blue:94), "jam":(red:165,green:11,blue:94) ] //var backView = UIView(frame: CGRect(x:0, y:0, width: 320, height:colors.count * 50) var backView = UIView(frame:CGRect(x: 0.0, y: 0.0, width: 320.0, height: CGFloat(colors.count * 50)) ) backView.backgroundColor = UIColor.black var index = 0 for (colorName,rgbTuple) in colors { var colorStripe = UILabel(frame: CGRect(x:0.0,y:CGFloat(index*50+5),width:320,height:40)) colorStripe.backgroundColor = UIColor(red: CGFloat(rgbTuple.red/255), green: CGFloat(rgbTuple.green/255), blue: CGFloat(rgbTuple.blue/255), alpha: 1.0) var colorNameLabel = UILabel(frame: CGRect(x:0.0 ,y:0.0, width:320.0, height:40.0)) colorNameLabel.font = UIFont(name: "Arial", size: 24.0) colorNameLabel.textAlignment = NSTextAlignment.right colorNameLabel.text = colorName colorStripe.addSubview(colorNameLabel) backView.addSubview(colorStripe) index+=1 }
