Swift

//: Playground - noun: a place where people can play

import UIKit

var dict = [1:"one", 2:"two", 3:"three", 4:"four"]

dict.count
dict.isEmpty

dict[1]
dict[66]

"课程名称: " + dict[1]!

// 添加和修改
dict[5] = "five"
dict[4] = "44444"
dict.updateValue("2222", forKey: 2);
dict

// 删除
dict[1] = nil;
dict.removeValueForKey(5)
dict

// 遍历
for (key, value) in dict {
    print("key:(key) value:(value)")
}

dict.keys
dict.values

for key in dict.keys {
    print(key)
}

for value in dict.values {
    print(value)
}