[Swift3 & iOS10] Dictionary

import UIKit
 
//Dictionary 선언
var legs1 = [String:Int]()
var legs2:Dictionary<String,Int>=[:]
var legs3:[String:Int] = [:]
 
legs3["ant"] = 6
legs3["snake"] = 0
print(legs3)    //["ant": 6, "snake": 0]
 
var legs4 = ["ant":6,"snake":0,"cheetah":4]
 
legs4["human"] = 2
print(legs4)    //["ant": 6, "snake": 0, "human": 2, "cheetah": 4] -> 순서가 없다
 
print(legs4["ant"]) //Optional(6) -> Optional Value라서 unwrapping해줘야 한다
print(legs4["ant"]!) //6
 
 
//immutable dictionary
let legs5 = ["ant":6,"snake":0,"cheetah":4]
//legs5["human"]=2    //추가할 경우 오류남