Objective-C 字典NSDictionary用法
//
// main.m
// KenshinCui
//
// Created by hxd_mac on 15-6-7.
// Copyright (c) 2015年 hxd198. All rights reserved.
//
#import <Foundation/Foundation.h>
#import "Person.h"
void Test1()
{
//初始化字典
//一般方式
NSDictionary *dict1 = [NSDictionary dictionaryWithObject:@"1" forKey:@"a"];
NSLog(@"dict1: %@", dict1);
//常见方式
NSDictionary *dict2 = [NSDictionary dictionaryWithObjectsAndKeys:@"1",@"a",@"2",@"b",@"3",@"c", nil];
NSLog(@"dict2: %@", dict2);
//嵌套方式
NSDictionary *dict3 = [NSDictionary dictionaryWithObject:[NSArray arrayWithObjects:@"value1",@"value2", nil] forKey:[NSArray arrayWithObjects:@"key1",@"key2", nil]];
NSLog(@"dict3: %@", dict3);
//最简单方式
NSDictionary *dict4 = @{@"1": @"a", @"2": @"b", @"3": @"c"};
NSLog(@"dict4: %@", dict4);
}
void Test2()
{
//字典一般用法
NSDictionary *dict1 = [NSDictionary dictionaryWithObjectsAndKeys:@"1",@"a",@"2",@"b",@"3",@"c",@"4",@"d", nil];
//统计个数
NSLog(@"count: %zi", [dict1 count]);
//key找value
//第一种方式
NSLog(@"value1: %@", [dict1 valueForKey:@"b"]);
//第二种方式
NSLog(@"value2: %@", dict1[@"b"]);
//第三种方式
NSLog(@"allValue: %@ , allKey: %@", [dict1 allValues], [dict1 allKeys]);
// NSLog(@"value and key: %@", [dict1 objectForKey:[NSArray arrayWithObjects:@"a",@"e", nil]notFoundMarker: @"not found"]);
}
void Test3()
{
//字典遍历三种方法
NSDictionary *dict1 = [NSDictionary dictionaryWithObjectsAndKeys:@"1",@"a",@"2",@"b",@"3",@"c",@"4",@"d", nil];
id key;
//常规遍历
for (key in dict1) {
NSLog(@"key: %@ value: %@", key, [dict1 objectForKey:key]);
}
//枚举快速遍历
NSEnumerator *enumerator = [dict1 keyEnumerator];
id obj = nil;
while ( obj = [enumerator nextObject]) {
NSLog(@"%@ = %@", obj, [dict1 objectForKey:obj]);
}
//块遍历
[dict1 enumerateKeysAndObjectsUsingBlock: ^(id key , id obj, BOOL *stop){
NSLog(@"key = %@, obj = %@", key, obj);
}];
}
void Test4()
{
//可变字典的一般用法
NSMutableDictionary *dict1 = [NSMutableDictionary dictionaryWithObjectsAndKeys:@"1",@"a",@"2",@"b",@"3",@"c",@"4",@"d", nil];
//移除对象
[dict1 removeObjectForKey:@"b"];
NSLog(@"after remove:%@", dict1);
//添加对象
[dict1 addEntriesFromDictionary:[NSDictionary dictionaryWithObjectsAndKeys:@"5",@"e",@"6",@"f", nil]];
NSLog(@"after add: %@", dict1);
//重置对象的值
[dict1 setValue:@"7" forKey:@"a"];
NSLog(@"after set: %@", dict1);
}
int main(int argc, const char * argv[])
{
@autoreleasepool {
Test1();
Test2();
Test3();
Test4();
}
return 0;
}
输出结果：
2015-06-08 20:42:49.632 KenshinCui[596:303] dict1: {
a = 1;
}
2015-06-08 20:42:49.639 KenshinCui[596:303] dict2: {
a = 1;
b = 2;
c = 3;
}
2015-06-08 20:42:49.641 KenshinCui[596:303] dict3: {
(
key1,
key2
) = (
value1,
value2
);
}
2015-06-08 20:42:49.642 KenshinCui[596:303] dict4: {
1 = a;
2 = b;
3 = c;
}
2015-06-08 20:42:49.644 KenshinCui[596:303] count: 4
2015-06-08 20:42:49.646 KenshinCui[596:303] value1: 2
2015-06-08 20:42:49.648 KenshinCui[596:303] value2: 2
2015-06-08 20:42:49.649 KenshinCui[596:303] allValue: (
4,
2,
3,
1
) , allKey: (
d,
b,
c,
a
)
2015-06-08 20:42:49.650 KenshinCui[596:303] key: d value: 4
2015-06-08 20:42:49.651 KenshinCui[596:303] key: b value: 2
2015-06-08 20:42:49.673 KenshinCui[596:303] key: c value: 3
2015-06-08 20:42:49.675 KenshinCui[596:303] key: a value: 1
2015-06-08 20:42:49.817 KenshinCui[596:303] d = 4
2015-06-08 20:42:49.818 KenshinCui[596:303] b = 2
2015-06-08 20:42:49.819 KenshinCui[596:303] c = 3
2015-06-08 20:42:49.820 KenshinCui[596:303] a = 1
2015-06-08 20:42:49.821 KenshinCui[596:303] key = d, obj = 4
2015-06-08 20:42:49.822 KenshinCui[596:303] key = b, obj = 2
2015-06-08 20:42:49.824 KenshinCui[596:303] key = c, obj = 3
2015-06-08 20:42:49.826 KenshinCui[596:303] key = a, obj = 1
2015-06-08 20:42:49.829 KenshinCui[596:303] after remove:{
a = 1;
c = 3;
d = 4;
}
2015-06-08 20:42:49.831 KenshinCui[596:303] after add: {
a = 1;
c = 3;
d = 4;
e = 5;
f = 6;
}
2015-06-08 20:42:49.833 KenshinCui[596:303] after set: {
a = 7;
c = 3;
d = 4;
e = 5;
f = 6;
}