swift字符串,数组,字典和集合的遍历

//字符串的遍历
print("字符串遍历")
var str = "China"
for item in str.characters {
print(item)
}
print("+++++++++++++++++++")
for item in str.characters.indices {
print(str[item])
}
print("+++++++++++++++++++")
var i = 0
while i < str.characters.count {
var index = str.index(str.startIndex, offsetBy: i)
print(str[index])
i += 1
}

//数组的遍历
print("数组遍历")
var arr = [23,1,45,6,78]

for item in arr {
print(item)
}
print("+++++++++++++++++++")
for (index,value) in arr.enumerated() {
print(index,value)
}
print("+++++++++++++++++++")
var j = 0
while j < arr.count {
print(j,arr[j])
j += 1
}

//集合遍历
print("集合遍历")
var set:Set<String> = []
set = ["china","beijing","朝阳"]

for item in set {
print(item)
}
print("+++++++++++++++++++")
for ( i,item) in set.sorted().enumerated() {
print(i,item)
}
//字典遍历
print("字典遍历")
var dic = [1001:"C",1002:"OC",1003:"Java"]
dic[1005] = "C++"

for item in dic {
print(item)
}
print("+++++++++++++++++++")
for item in dic.keys {
print(item,dic[item]!)
}
print("+++++++++++++++++++")
for item in dic.values {
print(item)
}