Swift collection: array, set,dictionary

// 1. Collection : Array
var a = [Int]()
var b = Array(repeating: 4, count: 3)
print(a)
print(b)
a = [1,2,3]
var c = a + b
print(c)
c += [5,6]
print(c)

c[2...5] = [9,10]  //it's brilliant way.
print(c)
for (index, val) in c.enumerated(){
    print( "\(index) => \(val)" )
}



// 2. Collection : Set
var even:Set<Int> = [2,4,6,8,10]
var odd:Set = [1,3,5,7,9]
var tmp = Set<Int>()
even.insert(12)
tmp = [2,3,4,5]

print(tmp.intersection(odd))
print(tmp.union(even))
print(tmp.symmetricDifference(even).sorted())

//3. Collection : Dictionary
var dict = [Int:String]()
dict = [:]
print(dict)

var airportCode = ["a":"america", "b":"bangkok", "c":"china"]
for( key, value ) in airportCode {
    print( "key:\(key) val:\(value)")
}