今天写一些Swift数组的增删改代码：
var courses = ["A","B","C"]
//添加元素
courses.append("D") //["A","B","C","D"]
print(courses)
//数组常量
//使用let定义的数组不可以更改任何内容
courses += ["E"] // +=后面必须和前面的类型保持一致 //["A","B","C","D","E"]
print(courses)
//两个数组相加
courses = courses + ["F","G"] //+后面必须是数组
// ["A","B","C","D","E","F","G"]
print(courses)
courses.insert("Q",at:5)
// ["A","B","C","D","E","F","Q","G"]
print(courses)
//删除元素
courses.removeLast()
//["A","B","C","D","E","Q","F"]
courses.removeFirst()
//["B","C","D","E","Q","F"]
print(courses)
courses.remove(at:4)
//["B","C","D","E","F"]
//courses.removeAtIndex(10)
print(courses)
//区间删除操作
//courses.removeRange(0..<4)
//courses.removeAtIndex(0..<10)
//print(courses)
//courses.removeAll()
//print(courses)
//修改元素
courses[0] = "W"
//["W","C","D","E","F"]
print(courses)
//范围修改
courses[1...3] = ["W","W","W"]
//["W","W","W","W","F"]
print(courses)
以上是数组的增删改的操作，希望对广大读者有所帮助。
另外，NSArray是一个类，Array是一个结构体
var array1 = [] //默认是NSArray，Swift3.0之后这个写法被废除
var array2 = [1,2,3,4,5] as NSArray
var array3:NSArray = [1,"hello"]
var array4:[NSObject] = [1,as NSObject,"hello" as NSObject]
