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;
}