Array

import UIKit

 

// Array (배열)

 

// 배열선언

// => var 변수명: Array<데이터형> = [내용]

 

var names: Array<String> = ["yagom", "chulsoo", "younghee", "yagom" ]

//var names: [String] = ["yagom", "chulsoo", "younghee", "yagom" ]

print(names)

/// ["yagom", "chulsoo", "younghee", "yagom"]

 

 

// 빈 배열 생성하기()

var emptyArray: [Any] = [Any]()

//var emptyArray: [Any] = Array<Any>()

// 타입을 정확히 명시하는 경우 []로도 빈 배열 생성 가능

//var emptyArray: [Any] = []

print(emptyArray.isEmpty) ///  true

print(names.count) ///  4

 

print(names[2]) /// younghee

names[2] = "jenny"

print(names[2]) /// jenny

//print(names[4]) // ERROR

names.append("elsa")

print(names) /// ->  ["yagom", "chulsoo", "jenny", "yagom", "elsa"]

names.append(contentsOf: ["john", "max"])

print(names) /// ->  ["yagom", "chulsoo", "jenny", "yagom", "elsa", "john", "max"]

names.insert("happy", at: 2)

print(names) /// -> ["yagom", "chulsoo", "happy", "jenny", "yagom", "elsa", "john", "max"]

names.insert(contentsOf: ["jinhee", "minsoo"], at: 5)

print(names)

/// -> ["yagom", "chulsoo", "happy", "jenny", "yagom", "jinhee", "minsoo", "elsa", "john", "max"]

 

print(names[4]) // -> yagom

// firstIndex: 해당요소의 인덱스 알아내기

print(names.firstIndex(of: "yagom")) /// Optional(0)

print(names.firstIndex(of: "christal")) /// nil

print(names.first) /// Optional("yagom")

print(names.last) /// Optional("max")

 

print(names.count) /// 10

let firstItem: String = names.removeFirst()

print(names.count) /// 9

let lastItem: String = names.removeLast()

let indexZeroItem: String = names.remove(at: 0)

print(names.count) /// 7

print(names[1...3]) /// ["jenny", "yagom", "jinhee"]

 

import UIKit


// Array (배열)

// 배열선언
// => var 변수명: Array<데이터형> = [내용]

var names: Array<String> = ["yagom", "chulsoo", "younghee", "yagom" ]
//var names: [String] = ["yagom", "chulsoo", "younghee", "yagom" ]
print(names)
/// ["yagom", "chulsoo", "younghee", "yagom"]


// 빈 배열 생성하기()
var emptyArray: [Any] = [Any]()
//var emptyArray: [Any] = Array<Any>()
// 타입을 정확히 명시하는 경우 []로도 빈 배열 생성 가능
//var emptyArray: [Any] = []
print(emptyArray.isEmpty) ///  true
print(names.count) ///  4

print(names[2]) /// younghee
names[2] = "jenny"
print(names[2]) /// jenny
//print(names[4]) // ERROR
names.append("elsa")
print(names) /// ->  ["yagom", "chulsoo", "jenny", "yagom", "elsa"]
names.append(contentsOf: ["john", "max"])
print(names) /// ->  ["yagom", "chulsoo", "jenny", "yagom", "elsa", "john", "max"]
names.insert("happy", at: 2)
print(names) /// -> ["yagom", "chulsoo", "happy", "jenny", "yagom", "elsa", "john", "max"]
names.insert(contentsOf: ["jinhee", "minsoo"], at: 5)
print(names)
/// -> ["yagom", "chulsoo", "happy", "jenny", "yagom", "jinhee", "minsoo", "elsa", "john", "max"]

print(names[4]) // -> yagom
// firstIndex: 해당요소의 인덱스 알아내기
print(names.firstIndex(of: "yagom")) /// Optional(0)
print(names.firstIndex(of: "christal")) /// nil
print(names.first) /// Optional("yagom")
print(names.last) /// Optional("max")

print(names.count) /// 10
let firstItem: String = names.removeFirst()
print(names.count) /// 9
let lastItem: String = names.removeLast()
let indexZeroItem: String = names.remove(at: 0)
print(names.count) /// 7
print(names[1...3]) /// ["jenny", "yagom", "jinhee"]