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Swift數組詳細用法解析

2020-03-09 17:47:18
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一、說明

Swift數組中的類型必須一致,這一點與OC不同

// 數組初始化var numbers = [0,1,2,3,4,5]var vowels = ["A","E","I","O","U"]// 數組的類型: [Int] 或者 Array<Int>//var numbers: [Int] = [0,1,2,3,4,5]//var numbers: Array<Int> = [0,1,2,3,4,5]// 空數組var emptyArray1:[Int] = []var emptyArray2:Array<Int> = []var emptyArray3 = [Int]()var emptyArray4 = Array<Int>()// 創建具有默認值的數組(相同元素的數組)var allZeros = Array<Int>(repeating: 0, count: 5)//[0,0,0,0,0]var allZeros2 = [Int](repeating: 0, count: 5)//[0,0,0,0,0]

二、常用方法

var numbers = [1,2,3,4,5]var vowels = ["A","E","I","O","U"]var emptyArray = [Int]()// 數組長度vowels.count// 判空numbers.isEmptyemptyArray.isEmpty// 獲取元素vowels[2]// 數組越界是一個嚴重的錯誤//vowels[-1]//vowels[5]// 獲取第一個元素和最后一個元素,返回的是可選型vowels.first vowels.last  //.first和.last的返回值都為可選型emptyArray.firstif let firstVowel = vowels.first{  print("The first vowel is " + firstVowel)}vowels.first!vowels[vowels.count-1]// 獲取最小,最大值numbers.min() //1vowels.max() //U// 使用范圍numbers[2..<4] //[3,4]numbers[2..<numbers.count] //[3,4,5]// 包含vowels.contains("A")vowels.contains("B")let letter = "A"if vowels.contains( letter ){  print("/(letter) is a vowel")}else{  print("/(letter) is not a vowel")}vowels.index(of: "E") //獲取索引,返回值為可選型if let index = vowels.index(of: "E"){  print("E is a vowel in position /(index+1).")}else{  print("E is not a vowel.")}// 遍歷for index in 0..<numbers.count{  numbers[index]}for number in numbers{  print(number)}for (index, vowel) in vowels.enumerated(){  //遍歷數組索引和元素  print("/(index+1): /(vowel)")}// 比較var oneToFive = [1,2,3,4,5]numbers == oneToFive //truevar oneToFive2 = [1,2,4,3,5]numbers == oneToFive //true//swift 3.0之前數組是有序的數據集合,swift 3.0后為無序

三、更多操作

var courses = ["A","B","C"]// 添加元素courses.append("D") //["A","B","C","D"]print(courses)// 數組常量//使用let定義的數組不可以更改任何內容courses += ["E"] //+=后面必須和前面的類型一致 //["A","B","C","D","E"]print(courses)// 兩個數組相加courses = courses + ["F","G"] //+后面必須是數組//["A","B","C","D","E","F","G"]print(courses)courses.insert("Q", at: 5) //["A", "B", "C", "D", "E", "Q", "F", "G"]print(courses)// 刪除元素courses.removeLast()//["A", "B", "C", "D", "E", "Q", "F"]print(courses)courses.removeFirst()//["B", "C", "D", "E", "Q", "F"]print(courses)courses.remove(at: 4)//["B", "C", "D", "E", "F"]//courses.removeAtIndex(10)print(courses)//區間刪除操作//courses.removeRange(0..<4)//courses.removeRange(0..<10)//print(courses)//courses.removeAll()//print(courses)// 修改元素courses[0] = "W"//["W", "C", "D", "E", "F"]print(courses)//范圍修改courses[1...3] = ["W","W","W"]//["W", "W", "W", "W", "F"]print(courses)courses[0...3] = ["W"]//["W", "F"]print(courses)

四、二維數組

var board = [ [1024,16,2,0] , [256,4,2,0] , [64,2,0,0] , [2,0,0,0] ]//var board:[[Int]] = [ [1024,16,2,0] , [256,4,2,0] , [64,2,0,0] , [2,0,0,0] ]//var board:[Array<Int>] = = [ [1024,16,2,0] , [256,4,2,0] , [64,2,0,0] , [2,0,0,0] ]//var board:Array<[Int]> = [ [1024,16,2,0] , [256,4,2,0] , [64,2,0,0] , [2,0,0,0] ]//var board:Array<Array<Int>> = [ [1024,16,2,0] , [256,4,2,0] , [64,2,0,0] , [2,0,0,0] ]// 二維數組獲取元素board[0]board[0][0]// 獲取二維數組兩個維度的信息board.countboard[0].count// Swift中的二維數組,每一維度的元素數目可以不同board[0].append(0)board// 為二維數組的第一個維度添加的元素是一個數組board.append([0,0,0,0])board += [ [0,0,0,0] ]board

五、NSArray

NSArray是一個類,Array是一個結構體

var array1 = [] //會默認是NSArray,swift3.0之后該寫法廢除var array2 = [1,2,3,4,5] as NSArrayvar array3: NSArray = [1,"hello"]var array4: [NSObject] = [1 as NSObject,"hello" as NSObject]

以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支持VEVB武林網。


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