//1、保存字典对象内容到文件
[dict3 writeToFile:@"/Users/apple/Desktop/tesk.txt" atomically:YES]; //2、从之前保存的文件读取数据到字典对象
NSDictionary *dict4=[NSDictionary dictionaryWithContentsOfFile:@"/Users/apple/Desktop/tesk.txt"]; NSLog(@"dict4:%@",dict4);
1 //1、分别获取字典的所有键、值
2 NSArray *allkeys=[dict1 allKeys]; 3 NSLog(@"allkeys:%@",allkeys); 4 NSArray *allvalues=[dict1 allValues]; 5 NSLog(@"allvalues:%@",allvalues); 6
7 //2、通过指定的key取对应的value对象,没有这个key的话.返回nil
8 NSNumber *num1 = [dict1 objectForKey:@"key1"]; 9 NSNumber *num2 = [dict1 objectForKey:@"key5"]; 10 NSLog(@"%@",num1); 11 NSLog(@"%@",num2); 12
13 //3、获取字典中键值对的个数
14 NSUInteger paircount=[dict2 count]; 15 NSLog(@"%lu",paircount);
1 for (id key in dict1) { 2 id value=[dict1 objectForKey:key]; 3 NSLog(@"%@=%@",key,value); 4 }
2015-04-07 21:17:53.933 NSDictionary[5465:226991] dict01:{
value0 = key0;
value1 = key1;
value2 = key2;
}
2015-04-07 21:17:53.934 NSDictionary[5465:226991] dict1:{
key0 = 123;
key1 = 456;
key2 = 678;
}
2015-04-07 21:17:53.934 NSDictionary[5465:226991] dict02:{
hong = name0;
wang = name1;
zhao = name2;
}
2015-04-07 21:17:53.934 NSDictionary[5465:226991] dict2:{
name0 = hong;
name1 = wang;
name2 = zhao;
}
2015-04-07 21:17:53.935 NSDictionary[5465:226991] dict03:{
key0 = 123;
key1 = 456;
key2 = 678;
}
2015-04-07 21:17:53.935 NSDictionary[5465:226991] dict3:{
key0 = 123;
key1 = 456;
key2 = 678;
}
2015-04-07 21:17:53.937 NSDictionary[5465:226991] dict4:{
key0 = 123;
key1 = 456;
key2 = 678;
}
2015-04-07 21:17:53.938 NSDictionary[5465:226991] allkeys:(
key1,
key0,
key2
)
2015-04-07 21:17:53.938 NSDictionary[5465:226991] allvalues:(
456,
123,
678
)
2015-04-07 21:17:53.938 NSDictionary[5465:226991] num1:456
2015-04-07 21:17:53.938 NSDictionary[5465:226991] num2:(null)
2015-04-07 21:17:53.938 NSDictionary[5465:226991] 键值对个数:3
2015-04-07 21:17:53.938 NSDictionary[5465:226991] key1=456
2015-04-07 21:17:53.938 NSDictionary[5465:226991] key0=123
2015-04-07 21:17:53.938 NSDictionary[5465:226991] key2=678
运行结果分析
//可变数据字典初始化
NSMutableDictionary *mDict1=[NSMutableDictionary dictionaryWithObjectsAndKeys:@"aaa",@"name0",@"bbb",@"name1",@"ccc",@"name2", nil];
NSLog(@"%@",mDict1);
//1、加入元素到NSMutableDictionary中 (注意:当key值中存在要添加的键值对中的key值时,则添加,否则覆盖)
[mDict1 setObject:@"ddd" forKey:@"name3"];
[mDict1 setObject:@"eee" forKey:@"name1"];
NSLog(@"add: %@",mDict1);
//2、查看 中所有元素个数:
NSLog(@"%lu",mDict1.count);
NSNumber *num3 =[mDict1 objectForKey:@"name1"];
NSLog(@"%@",num3);
NSNumber *num4 = [mDict1 objectForKey:@"name10"];
NSLog(@"%@",num4);
//3、添加其他NSMutableDictionary
[mDict1 setValuesForKeysWithDictionary:dict1];
NSLog(@"++++%@",mDict1);
//4、根据key值删除
[mDict1 removeObjectForKey:@"name1"];
NSLog(@"---%@",mDict1);
//5、删除所有
[mDict1 removeAllObjects];
NSLog(@"%@",mDict1);
2015-04-07 22:12:10.717 NSDictionary[5827:248322] add: {
name0 = aaa;
name1 = eee;
name2 = ccc;
name3 = ddd;
}
2015-04-07 22:12:10.718 NSDictionary[5827:248322] 4
2015-04-07 22:12:10.718 NSDictionary[5827:248322] eee
2015-04-07 22:12:10.718 NSDictionary[5827:248322] (null)
2015-04-07 22:12:10.719 NSDictionary[5827:248322] ++++{
key0 = 123;
key1 = 456;
key2 = 678;
name0 = aaa;
name1 = eee;
name2 = ccc;
name3 = ddd;
}
2015-04-07 22:12:10.719 NSDictionary[5827:248322] ---{
key0 = 123;
key1 = 456;
key2 = 678;
name0 = aaa;
name2 = ccc;
name3 = ddd;
}
2015-04-07 22:12:10.719 NSDictionary[5827:248322] {
}
运行结果分析