Swift_数组详解
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初始化
//初始化
fileprivate func testInit() {
//空数组
var array = [Int]()
print(array)
array = []
print(array)
array = Array<Int>()
print(array)
//有数值的数组
array = [Int](repeating: 0, count: 3)
print(array)
array = [0, 0, 0]
print(array)
/* print
[]
[]
[]
[0, 0, 0]
[0, 0, 0]
*/
}
查询相关信息
//查询相关信息
fileprivate func testQuerying() {
var array = ["XuBaoAiChiYu", "QQ", "1045214799"]
print("contains:(array.contains("XuBaoAiChiYu"))") //是否存在这个元素
print("count:(array.count)") //有多少个元素
print("capacity:(array.capacity)") //有多少个元素
print("startIndex:(array.startIndex)") //首坐标
print("endIndex:(array.endIndex)") //尾脚标
print("first:(array.first)") //首元素
print("last:(array.last)") //尾元素
print("isEmpty:(array.isEmpty)") //是否为空
//获取指定位置的元素
var temp = (array as NSArray).object(at: 0)
temp = array[0]
print("(temp)")
//获取多个元素
let nRange : NSRange = NSMakeRange(0, 3)
let nIndexSet = IndexSet(integersIn: nRange.toRange() ?? 0..<0)
let ocArray = (array as NSArray).objects(at: nIndexSet)
print("(ocArray)")
let range = (0 ..< 3)
let sArray = array[range]
print("(sArray)")
//遍历
//只获取元素
for item in array {
print(item)
}
//遍历元素和所处的位置
for (index, value) in array.enumerated() {
print("(index):(value)")
}
/* print
contains:true
count:3
capacity:3
startIndex:0
endIndex:3
first:Optional("XuBaoAiChiYu")
last:Optional("1045214799")
isEmpty:false
XuBaoAiChiYu
[XuBaoAiChiYu, QQ, 1045214799]
["XuBaoAiChiYu", "QQ", "1045214799"]
XuBaoAiChiYu
QQ
1045214799
0:XuBaoAiChiYu
1:QQ
2:1045214799
*/
}
查找元素位置
//查找元素位置
fileprivate func testFindingObjects() {
let array = ["XuBaoAiChiYu", "QQ", "1045214799"]
// 查找元素
var index = array.index(of: "QQ")
print(index!)
// closures查找
index = array.index { (str:String) -> Bool in
if str == "QQ" {
return true
}
return false
}
print(index!)
// 简写
index = array.index{ str in return str == "QQ" }
print("index:(index)")
index = array.index{ str in str == "QQ" }
print("index:(index)")
index = array.index{ $0 == "QQ"}
print("index:(index)")
/* print
1
1
index:Optional(1)
index:Optional(1)
index:Optional(1)
*/
}
增加元素
//增加元素
fileprivate func testAdding() {
var array = [String]()
print(array)
//增加一个
array.append("XuBaoAiChiYu")
print(array)
array += ["XuBaoAiChiYu"]
print(array)
//增加多个
array.append(contentsOf: ["QQ", "1045214799"])
print(array)
array += ["QQ", "1045214799"]
print(array)
//插入
array.insert("1045214799", at: 0)
print(array)
//插入多个
array.insert(contentsOf: ["1045214799", "QQ"], at: 0)
print(array)
/* print
[]
["XuBaoAiChiYu"]
["XuBaoAiChiYu", "XuBaoAiChiYu"]
["XuBaoAiChiYu", "XuBaoAiChiYu", "QQ", "1045214799"]
["XuBaoAiChiYu", "XuBaoAiChiYu", "QQ", "1045214799", "QQ", "1045214799"]
["1045214799", "XuBaoAiChiYu", "XuBaoAiChiYu", "QQ", "1045214799", "QQ", "1045214799"]
["1045214799", "QQ", "1045214799", "XuBaoAiChiYu", "XuBaoAiChiYu", "QQ", "1045214799", "QQ", "1045214799"]
*/
}
删除元素
//删除元素
fileprivate func testRemoving() {
var array = ["XuBaoAiChiYu", "QQ", "1045214799"]
print(array)
array = array + array + array + array
print(array)
var temp = array.removeFirst() //删除首个元素 并返回删除的元素
print(array)
print(temp)
array.removeFirst(2) //删除前两个元素
print(array)
temp = array.removeLast() //删除最后一个元素
print(array)
temp = array.remove(at: 0) //删除指定位置的元素
print(array)
array.removeSubrange((array.indices.suffix(from: 0))) //删除指定范围的元素
print(array)
array.removeAll() //删除所有元素
print(array)
/* print
["XuBaoAiChiYu", "QQ", "1045214799"]
["XuBaoAiChiYu", "QQ", "1045214799", "XuBaoAiChiYu", "QQ", "1045214799", "XuBaoAiChiYu", "QQ", "1045214799", "XuBaoAiChiYu", "QQ", "1045214799"]
["QQ", "1045214799", "XuBaoAiChiYu", "QQ", "1045214799", "XuBaoAiChiYu", "QQ", "1045214799", "XuBaoAiChiYu", "QQ", "1045214799"]
XuBaoAiChiYu
["XuBaoAiChiYu", "QQ", "1045214799", "XuBaoAiChiYu", "QQ", "1045214799", "XuBaoAiChiYu", "QQ", "1045214799"]
["XuBaoAiChiYu", "QQ", "1045214799", "XuBaoAiChiYu", "QQ", "1045214799", "XuBaoAiChiYu", "QQ"]
["QQ", "1045214799", "XuBaoAiChiYu", "QQ", "1045214799", "XuBaoAiChiYu", "QQ"]
[]
[]
*/
}
替换元素
//替换元素
fileprivate func testReplacing() {
var array = ["XuBaoAiChiYu", "QQ", "1045214799"]
print(array)
array[1] = "iOS" // 替换指定位置的元素
print(array)
// 替换指定范围的元素
array[0..<3] = ["a", "b", "c"]
print(array)
let subRange: CountableRange<Int> = (array.indices.suffix(from: 1))
array.replaceSubrange(subRange, with: ["c","d","e"])
print(array)
/* print
["XuBaoAiChiYu", "QQ", "1045214799"]
["XuBaoAiChiYu", "iOS", "1045214799"]
["a", "b", "c"]
["a", "c", "d", "e"]
*/
}
排序
//排序
fileprivate func testSorting() {
var array = ["XuBaoAiChiYu", "QQ", "1045214799"]
print(array)
array = array.sorted()
print(array)
//自定义排序
func backwards(_ s1: String, _ s2: String) -> Bool {
return s1 > s2
}
array = array.sorted(by: backwards)
print(array)
//简写
array = array.sorted(by: { (s1: String, s2: String) -> Bool in
return s1 > s2
})
print(array)
array = array.sorted(by: <)
print(array)
/* print
["XuBaoAiChiYu", "QQ", "1045214799"]
["1045214799", "QQ", "XuBaoAiChiYu"]
["XuBaoAiChiYu", "QQ", "1045214799"]
["XuBaoAiChiYu", "QQ", "1045214799"]
["1045214799", "QQ", "XuBaoAiChiYu"]
*/
}
文件读和写
//文件读和写
fileprivate func testReadingAndWriting() {
//Document目录
let documents:[String] = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true)
let docDirPath = documents.first!
let path = (docDirPath as NSString).appendingPathComponent("test.plist")
let url = URL(fileURLWithPath: path)
var array = ["XuBaoAiChiYu", "QQ", "1045214799"]
//写
(array as NSArray).write(toFile: path, atomically: true)
(array as NSArray).write(to: url, atomically: true)
//读
array = NSArray(contentsOfFile: path) as! Array
print(array)
array = NSArray(contentsOf: url) as! Array
print(array)
/* print
["XuBaoAiChiYu", "QQ", "1045214799"]
["XuBaoAiChiYu", "QQ", "1045214799"]
*/
}