Swift-字典

//
//  main.swift
//  DictonaryDemo
//
//  Created by 程磊 on 15/5/20.
//  copyright (c) 2015年 chenglei. All rights reserved.
//

import Foundation

//字典的使用

let emptyDic1 = [:];//声明一个空的字典
let emptyDic2 = Dictionary<String,Float>();//声明一个空的字典，key为String类型，value为Float类型

var airports = ["TYO":"Tokyo","CN":"China","CD":"Canada"];
println(airports);

//添加修改
airports["USA"] = "American";//如果存在key则是修改，否则则是添加
println(airports);

//删除的方式有两种，1将字典中对应的value值设置nil，2.使用系统提供的方法，删除指定的value
airports["TYO"] = nil;
println(airports);

airports.removeValueForKey("USA");
println(airports);

//输出count
println("airports count is \(airports.count)");
println("airports count is " + String(airports.count));

//遍历字典
for (key,value) in airports {
    println("key = \(key),value = \(value)");
}

//遍历所有的key
for key in airports.keys {
    println("key = \(key)");
}

//遍历所有的value
for value in airports.values {
    println("value = \(value)");
}

//将对应的values以及keys转化为数组
let allKeys = Array(airports.keys);
let allValues = Array(airports.values);
println(allKeys);
println(allValues);