Object -C Dictionary -- 笔记

//

//  main.m

//  dictionary

//

//  Created by facial on 24/8/15.

//  Copyright (c) 2015 facial_huo. All rights reserved.

//

#import <Foundation/Foundation.h>

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

@autoreleasepool {

// insert code here...

NSLog(@"Hello, World!");

NSDictionary *dict = [[NSDictionary alloc] initWithObjectsAndKeys:

@"one", @"1",

@"three", @"3",

@"two", @"2",

nil ];

//Dictionary

//快速枚举法

for(id item in dict) {

NSLog(@"%@", item);

}

//遍历 key 通过key取得value

NSEnumerator *keyEnume = [dict keyEnumerator];

id obj;

while (obj = [keyEnume nextObject]) {

NSLog(@"%@, %@", obj, [dict objectForKey: obj]);

}

//遍历value

NSEnumerator *valueEnume = [dict objectEnumerator];

id obj2;

while ( obj2 = [valueEnume nextObject]) {

NSLog(@"%@", obj2);

}

//通过key取value

NSString *str;

str = [dict valueForKey: @"2"];   // str = two

NSLog(@"%@", str);

// MutableDictionary

//初始化MutableDictionary , 添加键值对

NSMutableDictionary *mutableDict = [NSMutableDictionary new];

[mutableDict setObject: @"yellow" forKey: @"1"];

[mutableDict setObject: @"red" forKey: @"2"];

[mutableDict setObject: @"black" forKey: @"3"];

NSLog(@"%@", mutableDict);

//删除单个键值对

[mutableDict removeObjectForKey: @"1"];

//删除多个键值

NSArray *array = [NSArray arrayWithObjects: @"1", @"2", nil];

[mutableDict removeObjectsForKeys:array];

NSLog(@"%@", mutableDict);

}

return 0;

}