1、数组添加某一个值
var arradd = ["11","22","33","44","55"]
print("arradd返回的类型是:--->\(type(of: arradd))");
print("arradd=\(arradd)");
//数组添加某一个值
arradd.append("66")//向数组最后添加一个元素
print("arradd=\(arradd)");
arradd.insert("77", at: 2)//向数组下标为2的地方插入一个元素
print("arradd=\(arradd)");
let arradd1 = ["0011","0022","0033","0044","0055"]
arradd.append(contentsOf: arradd1)//向数组末尾插入数组
print("arradd=\(arradd)");
let arradd2 = ["啦啦","哈哈","嗷嗷","啊啊","永远"]
arradd.insert(contentsOf: arradd2, at: 4)//向数组下标为4的地方插入一个数组
print("arradd=\(arradd)");
2、数组删除某一个值
var arrdelete = ["11","22","33","44","55","66","77","88","99"]
print("arrdelete返回的类型是:--->\(type(of: arrdelete))");
print("arrdelete=\(arrdelete)");
arrdelete.remove(at: 2)//根据下标移除元素
print("arrdelete=\(arrdelete)");
arrdelete.removeFirst()//移除数组中第一个元素
print("arrdelete=\(arrdelete)");
arrdelete.removeLast()//移除数组中最后一个元素
print("arrdelete=\(arrdelete)");
print("------------------ 这个是一个分割线 ---------------")
var arrdelete1 = ["11","22","33","44","55","66","77","88","99"]
print("arrdelete1=\(arrdelete1)");
arrdelete1.removeFirst(3)//移除数组中前3个元素
print("arrdelete1=\(arrdelete1)");
arrdelete1.removeLast(2)//移除数组中后2个元素
print("arrdelete1=\(arrdelete1)");
arrdelete1.removeAll()//移除数组中所有元素
print("arrdelete1=\(arrdelete1)");
3、获取指定位置数据
let arrget = ["11","22","33","44","55","66","77","88","99"]
print("arrget=\(arrget)");
print("arrget第一个元素=\(arrget.first!)")//获取素组中第一个元素
print("arrget最后一个元素=\(arrget.last!)")//获取数组中最后一个元素
print("arrget下标为5的元素=\(arrget[5])")//获取数组中下标为5的元素
4、数组遍历
let arrtraverse = ["11","22","33","44","55","66","77","88","99"]
print("arrtraverse=\(arrtraverse)");
第一种: for - in
for model in arrtraverse{
print("值为:\(model)");
}
第二种:区间遍历
for idx in 0...arrtraverse.count-1 {
print("下标为:\(idx) 值为:\(arrtraverse[idx])");
}
第三种:反向遍历
for idx in arrtraverse.reversed() {
print("反向:idx =\(idx)");
}
第四种:有时候我们需要知道当前遍历数组的下标
for model in arrtraverse.enumerated(){
print("下标为:\(model.offset) 值为:\(model.element)");
}
第五种:map
arrtraverse.map { (element) in
print("值为:\(element)");
}
第六种:forEach
arrtraverse.forEach { (element) in
print("值为:\(element)");
}
第七种:跨步遍历(如:从0开始每隔2个打印一次)
for idx in stride(from: arrtraverse.startIndex, to: arrtraverse.endIndex, by: 2) {
print("跨步idx = \(arrtraverse[idx])");
}
根据某一条件获取符合条件的元素(如:找出数组中大于3的元素)
let arrInt:[Int] = [1,2,3,4,5]
let result = arrInt.filter { (element) -> Bool in
return element > 3
}
print("值为:\(result)");
5、数组包含
let arrcontains = ["11","22","33","44","55","66","77","88","99"]
print(arrcontains.contains("55"))
6、数组最值
let arrInt1:[Int] = [1,2,3,4,5]
print((arrInt1.max()!))
print((arrInt1.min()!))
7、数组排序
升序
let arrInt2 = [1,2,9,3,6,4,10,5]
let result1 = arrInt2.sorted()//数组升序
print(result1)
//也可以这样写
// let result1 = arrInt2.sorted { (x, y) -> Bool in
// return x < y
// }
降序
let result2 = arrInt2.sorted { (x, y) -> Bool in
return x > y
}
print(result2)
常用例子
var userList = [UserInfo]()
let userinfo1 = UserInfo()
userinfo1.name = "张三"
userinfo1.phone = "4234"
userinfo1.age = 29
userList.append(userinfo1)
let userinfo2 = UserInfo()
userinfo2.name = "李四"
userinfo2.phone = "1212"
userinfo2.age = 40
userList.append(userinfo2)
let userinfo4 = UserInfo()
userinfo4.name = "赵六"
userinfo4.phone = "1232"
userinfo4.age = 30
userList.append(userinfo4)
let userinfo3 = UserInfo()
userinfo3.name = "王五"
userinfo3.phone = "3525"
userinfo3.age = 25
userList.append(userinfo3)
userList.forEach { (model) in
print(model.name!)
}
print("------------------ 这个是一个分割线 ---------------")
let aa = userList.sorted { (model1:UserInfo, model2:UserInfo) -> Bool in
return model1.age! < model2.age!
}
aa.forEach { (model) in
print(model.name!)
}
class UserInfo {
var name:String?
var phone:String?
var age:Int?
}