NSDictionary 常用方法学习

阳光穿透心脏的1/2处 2022-08-07 13:50 136阅读 0赞

//
    //  NSDictionaryStu.m
    //  OC基础学习
    //
    //  Created by 麦子 on 15/4/13.
    //  Copyright (c) 2015年 麦子. All rights reserved.
    //
    
    #import "NSDictionaryStu.h"
    
    @implementation NSDictionaryStu
    
    
    -(void) dictionaryStu
    {
    
        NSLog(@"NSDictionary 学习");
        
        /**
         
          这个类就相当于java中的map类， 键值对的形式存在， key 和  value，  字典对象中的键和值不可以为空（nil）， 如果需要的话需要使用NSNull，这种包装类。
         
           它也有可变字典类，子类。  NSMutableDictionary,   数组用nil来进行结束
         */
    
        
        
        /*************** 初始化**************/
        
        NSDictionary  *dictionary = [NSDictionary dictionaryWithObject:@"value-1" forKey:@"key-1"]; // 单个创建
        NSLog(@"dictionary-1----%@",dictionary);
        
        
        NSDictionary *dictionaryArray = [NSDictionary dictionaryWithObjectsAndKeys:@"val-1",@"key-1",@"val-2",@"key-2", nil];//创建多个
        NSLog(@"dictionary-2-----%@",dictionaryArray);
        
        NSDictionary *dictionaryCopy = [NSDictionary dictionaryWithDictionary:dictionaryArray];// copy 原来的数组
        NSLog(@"dictionary-3----%@",dictionaryCopy);
        
        
        
        // 获取字典数量
        int number = [dictionaryArray count];
        NSLog(@"---%d",number);
        
        // 通过key获取val
        NSString  *val = [dictionaryArray objectForKey:@"key-1"];
        NSLog(@"val---%@",val);
        
        
        // 获取所有的key和val
        NSArray  *arrayKeys = [dictionaryArray allKeys];
        NSArray  *arrayVals = [dictionaryArray allValues];
        NSLog(@"key---%@----val----%@",arrayKeys,arrayVals);
        
        
        
        /************** NSMutableDictionary 可变字典 *******/
        NSMutableDictionary *mutableDictionary = [NSMutableDictionary dictionaryWithObjectsAndKeys:@"obj-1",@"key-1",@"obj-2",@"key-2",@"obj-3",@"key-3",@"obj-4",@"key-4", nil];
        NSDictionary *addDictionary = [NSDictionary dictionaryWithObject:@"obj-3" forKey:@"key-3"];
        [mutableDictionary addEntriesFromDictionary:addDictionary]; // 添加一个字典，到原来的字典中，这个方法是返回void
        NSLog(@"----%@",mutableDictionary);
        
        [mutableDictionary setValue:@"maizi-today" forKey:@"key-3"];//重新设置值
         NSLog(@"----%@",mutableDictionary);
        
        // 放入另一个字典中
        NSMutableDictionary  *dic = [NSMutableDictionary dictionary ]; // 空字典
        [dic setDictionary:mutableDictionary];
        NSLog(@"--********%@",dic);
        
        
         // 删除
        [mutableDictionary removeObjectForKey:@"key-1"];
        NSLog(@"---%@",mutableDictionary);
        
        // 删除一组
        NSArray *array = [NSArray arrayWithObjects:@"key-3",@"key-4", nil];
        [mutableDictionary removeObjectsForKeys:array];
        NSLog(@"---%@",mutableDictionary);
        
        // 删除所有
        [mutableDictionary removeAllObjects];
        NSLog(@"---%@",mutableDictionary);
        
        
        
        // 循环字典
        NSLog(@"%@",dic);
        
        for (int index = 0; index < [dic count]; index++) {
            
            id key = [[dic allKeys] objectAtIndex:index];
            id obj = [dic objectForKey:key];
            
            NSLog(@"---key--%@---val----%@---",key,obj);
            
        }
        
        
        for (id key in dic) {
            
            id obj = [dic objectForKey:key];
            
            NSLog(@"----**%@****----%@",key,obj);
            
        }
        
        
        
        id key;
        NSEnumerator *enmum = [dic keyEnumerator];
        while (key = [enmum nextObject]) {
            
            id object = [dic objectForKey:key];
            NSLog(@"*******----%@",object);
        };
    }
    
    @end

<span style="font-family: Arial, Helvetica, sans-serif;">运行结果如下：</span>

<span style="font-family: Arial, Helvetica, sans-serif;"></span><pre name="code" class="plain">2015-04-15 23:54:28.428 OC基础学习[1179:75792] NSDictionary 学习
    2015-04-15 23:54:28.429 OC基础学习[1179:75792] dictionary-1----{
        "key-1" = "value-1";
    }
    2015-04-15 23:54:28.429 OC基础学习[1179:75792] dictionary-2-----{
        "key-1" = "val-1";
        "key-2" = "val-2";
    }
    2015-04-15 23:54:28.429 OC基础学习[1179:75792] dictionary-3----{
        "key-1" = "val-1";
        "key-2" = "val-2";
    }
    2015-04-15 23:54:28.429 OC基础学习[1179:75792] ---2
    2015-04-15 23:54:28.429 OC基础学习[1179:75792] val---val-1
    2015-04-15 23:54:28.430 OC基础学习[1179:75792] key---(
        "key-1",
        "key-2"
    )----val----(
        "val-1",
        "val-2"
    )
    2015-04-15 23:54:28.430 OC基础学习[1179:75792] ----{
        "key-1" = "obj-1";
        "key-2" = "obj-2";
        "key-3" = "obj-3";
        "key-4" = "obj-4";
    }
    2015-04-15 23:54:28.430 OC基础学习[1179:75792] ----{
        "key-1" = "obj-1";
        "key-2" = "obj-2";
        "key-3" = "maizi-today";
        "key-4" = "obj-4";
    }
    2015-04-15 23:54:28.430 OC基础学习[1179:75792] --********{
        "key-1" = "obj-1";
        "key-2" = "obj-2";
        "key-3" = "maizi-today";
        "key-4" = "obj-4";
    }
    2015-04-15 23:54:28.448 OC基础学习[1179:75792] ---{
        "key-2" = "obj-2";
        "key-3" = "maizi-today";
        "key-4" = "obj-4";
    }
    2015-04-15 23:54:28.449 OC基础学习[1179:75792] ---{
        "key-2" = "obj-2";
    }
    2015-04-15 23:54:28.449 OC基础学习[1179:75792] ---{
    }
    2015-04-15 23:54:28.449 OC基础学习[1179:75792] {
        "key-1" = "obj-1";
        "key-2" = "obj-2";
        "key-3" = "maizi-today";
        "key-4" = "obj-4";
    }
    2015-04-15 23:54:28.449 OC基础学习[1179:75792] ---key--key-2---val----obj-2---
    2015-04-15 23:54:28.450 OC基础学习[1179:75792] ---key--key-1---val----obj-1---
    2015-04-15 23:54:28.450 OC基础学习[1179:75792] ---key--key-4---val----obj-4---
    2015-04-15 23:54:28.450 OC基础学习[1179:75792] ---key--key-3---val----maizi-today---
    2015-04-15 23:54:28.450 OC基础学习[1179:75792] ----**key-2****----obj-2
    2015-04-15 23:54:28.450 OC基础学习[1179:75792] ----**key-1****----obj-1
    2015-04-15 23:54:28.451 OC基础学习[1179:75792] ----**key-4****----obj-4
    2015-04-15 23:54:28.451 OC基础学习[1179:75792] ----**key-3****----maizi-today
    2015-04-15 23:54:28.470 OC基础学习[1179:75792] *******----obj-2
    2015-04-15 23:54:28.470 OC基础学习[1179:75792] *******----obj-1
    2015-04-15 23:54:28.470 OC基础学习[1179:75792] *******----obj-4
    2015-04-15 23:54:28.470 OC基础学习[1179:75792] *******----maizi-today
    Program ended with exit code: 0