Swift之数组

数组
一、数组的定义

var arr1 = [1,2,3,4]
var arr11:[Int] = [1,2,3,4]
var arr111:Array<Int> = [1,2,3,4]

空数组

//var arr2 = [] //你这个到底什么类型？无法推断
var arr2:[Int] = []
var arr22 = [Int]()

生成一个数组，10个元素，每个元素默认都是0

var arr3 = [Int](repeatElement(0,count:10))
print(arr3)

二、基本操作

print(arr3.count)//获取数组长度
print(arr2.isEmpty) //判断是否为空
print(arr1[1])//下标从0开始
print(arr1[1...3])
print(arr1[1...])
print(arr1[1..<3])
print(arr1.first!)//获取数组第一个
print(arr1.last!)

三、数组遍历
遍历1

for index in 0..<arr1.count{
    print(arr1[index])
}

遍历2

for number in arr1{
    print(number)
}

四、增删改查
增: 1)在末尾 2）在指定位置

var girlFriends = ["刘亦菲","迪丽热巴","杨幂","汤唯"]
girlFriends += ["刘诗诗"]
girlFriends.append("柳岩")
girlFriends.insert("翠花",at:0)

删除： 1）删除单个 2）删除一片

girlFriends.remove(at:3)
girlFriends.removeSubrange(2..<5)

改

girlFriends+=["迪丽","杨","唯"]
girlFriends[0]="红花"
girlFriends[2..<4]=["哈哈"]

查

print(girlFriends.contains("哈哈"))
print(girlFriends)