Object-c学习之路九（字典（NSDictionary&NSMutableDictionary））

字典的练习和使用（遍历，搜索。。。）（Student和Book类文件可以查看上篇博客这次不上传了。）

//
//  main.m
//  NSDictionary
//
//  Created by WildCat on 13-7-26.
//  Copyright (c) 2013年 wildcat. All rights reserved.
//


#pragma mark - NSDictionary练习

#import <Foundation/Foundation.h>
#import "Student.h"
#pragma  mark 创建字典
void dictCreat(){
    //第一种方式
    NSDictionary *dict=[NSDictionary dictionaryWithObjectsAndKeys:
                        @"v1",@"k1",
                        @"v2",@"k2",
                        @"v3",@"k3",nil];
    NSLog(@"The Dictionary is:%@",dict);
    //第二种方式
    NSArray *objects=[NSArray arrayWithObjects:@"v1",@"v2",@"v3",@"v4", nil];
    NSArray *keys=[NSArray arrayWithObjects:@"k1",@"k2",@"k3",@"k4", nil];
    dict=[NSDictionary dictionaryWithObjects:objects forKeys:keys];
    NSLog(@"The Dictionary is:%@",dict);
}

#pragma  mark 字典的使用
void dictUser(){

    //创建一个字典
    NSDictionary *dict=[NSDictionary dictionaryWithObjectsAndKeys:
                        @"v1",@"k1",
                        @"v2",@"k2",
                        @"v3",@"k3",nil];
    
    //由于NSDIctionary是不可变的，只能取值，不能修改值
    id obj=[dict objectForKey:@"k2"];//查找值
    NSLog(@"The obj is :%@",obj);
    NSInteger count=[dict count];//获得个数
    NSLog(@"Count :%zi",count);
    
    //将字典写入文件中
    NSString *path=@"/Users/bird/Desktop/dict.xml";
    [dict writeToFile:path atomically:YES];
    //通过keys获得values
    NSArray *objects=[dict objectsForKeys:[NSArray arrayWithObjects:@"k1",@"k2",@"k4", nil] notFoundMarker:@"not-finde"];
    NSLog(@"object:%@",objects);

}
#pragma  mark 遍历字典
void dictionaryFor(){
    NSDictionary *dict=[NSDictionary dictionaryWithObjectsAndKeys:
                        @"v1",@"k1",
                        @"v2",@"k2",
                        @"v3",@"k3",nil];
    //第一种方法
    for (id keys in dict) {
        id object=[dict objectForKey:keys];
        NSLog(@"%@--%@",keys,object);
    }

    //第二种方法  通过迭代器遍历
    NSEnumerator *keyenu=[dict keyEnumerator];
    id key=nil;
    NSLog(@"迭代器遍历：");
    while (key=[keyenu nextObject]) {
        id object=[dict objectForKey:key];
        NSLog(@"%@--%@",key,object);
    }

    NSLog(@"通过BLock遍历：");
     //第二种方法  通过Block遍历
    [dict enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
        NSLog(@"%@--%@",key,obj);

    }];
    


}

#pragma mark 可变字典
void mutableDictUser(){

    Student *stu1=[Student initWithFirstName:@"lele" LastName:@"li"];
    Student *stu2=[Student initWithFirstName:@"ll" LastName:@"li"];
    Student *stu3=[Student initWithFirstName:@"xingle" LastName:@"li"];
    NSMutableDictionary *dict=[NSMutableDictionary dictionary];

    [dict setValue:stu1 forKey:@"k1"];
    [dict setValue:stu2 forKey:@"k2"];
    [dict setValue:stu3 forKey:@"k3"];
    NSLog(@"%@",dict);
    //删除所有元素
    //[dict removeAllObjects];
    //通过键值删除元素
    [dict removeObjectForKey:@"k2"];

    NSLog(@"%@",dict);


}

int main(int argc, const char * argv[])
{

    @autoreleasepool {
        
        //dictCreat();
        //dictUser();
        
        //dictionaryFor();//遍历字典
        mutableDictUser();
        
    }
    return 0;
}