objectivec语法——Dictionary

//
//  main.m
//  Dictionary
//
//  Created by RD-Neil on 1/21/13.
//  Copyright (c) 2013 RD-Neil. All rights reserved.
//

#import <Foundation/Foundation.h>

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

    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    
    /*
     做过Java语言或者 C语言开发的朋友应该很清楚关键字map 吧,它可以将数据以键值对儿的形式储存起来,
     取值的时候通过KEY就可以直接拿到对应的值,非常方便。在Objective-C语言中词典对象就是做这个事情
     的,不过在同一个词典对象中可以保存多个不同类型的数据,不像Java与C只能保存声明的相同类型的数据,
     它的关键字为NSDictionary与NSMutableDictionary。阅读过我之前文章的朋友应该从关键字的结构就
     可以看出这两个的区别。很明显前者为不可变词典,或者为可变词典。
    */
    
    // 创建动态字典,初始化长度为10
    NSMutableDictionary *mutableDictionary = [NSMutableDictionary dictionaryWithCapacity:10];
    
    // 向字典中添加数据
    [mutableDictionary setObject:@"0.0" forKey:@"32.0"];
    [mutableDictionary setObject:@"100.0" forKey:@"212.0"];
    [mutableDictionary setObject:@"20.0" forKey:@"68.0"];
    [mutableDictionary setObject:@"-100.0" forKey:@"-148.0"];
    
    
    NSLog(@"mutableDictionarr:");
    // 通过key找到value
    NSLog(@"%@",[mutableDictionary objectForKey:@"32.0"]);
    NSLog(@"%@",[mutableDictionary objectForKey:@"212.0"]);
    NSLog(@"%@",[mutableDictionary objectForKey:@"68.0"]);
    NSLog(@"%@",[mutableDictionary objectForKey:@"-148.0"]);

    // 打印可变字典中所有key
    NSLog(@"all keys: %@", [mutableDictionary allKeys]);
    // 打印可变字典中所有value
    NSLog(@"all values: %@", [mutableDictionary allValues]);
    
    // 删除单个元素
    [mutableDictionary removeObjectForKey:@"32.0"];
   
    // 删除字典中所有元素
    [mutableDictionary removeAllObjects];
    
    // 增加一个元素
    [mutableDictionary setObject:@"00000.0" forKey:@"32.0"];
    NSLog(@"%@",[mutableDictionary objectForKey:@"32.0"]);
    
    
    
    
    
    
    
    // 静态字典
    NSDictionary *normalDictonary = [NSDictionary dictionaryWithObjectsAndKeys:@"Jenny", @"d1",
                                     @"Neil", @"d2", nil];
    // 通过key找到value
    NSString *d1 = [normalDictonary objectForKey:@"d1"];
   
    
    NSLog(@"normalDictionarr:");
    
    // 字典中所有的key
    NSLog(@"All keys: %@", [normalDictonary allKeys]);
    // 字典中所有的value
    NSLog(@"All values %@", [normalDictonary allValues]);
    NSLog(@"%@", d1);
    
    
    
    
    
    [pool release];

}
原文地址:https://www.cnblogs.com/viviJIE/p/2870236.html