可变字典的创建及读写 - 黑马程序员技术交流社区

#import <Foundation/Foundation.h>
int main(int argc, const char * argv[]) {
@autoreleasepool {
//在字典中汉字用utf8格式储存
NSDictionary *dict1=[NSDictionary dictionaryWithObject:@"张三" forKey:@"zs"];
NSLog(@"%@",dict1);
NSDictionary *dict2=[NSDictionary dictionaryWithObjectsAndKeys:@"詹桑",@"zs",@"温暖",@"wh", nil];
NSLog(@"%@",dict2);
}
//快速创建
NSDictionary *dict3=@{@"zs":@"zhangsna",@"ls":@"lisi"};
NSLog(@"%@",dict3);
//objectForKey 根据k值获取value值
NSString *s1= [dict3 objectForKey:@"zs"];
NSLog(@"%@",s1);
//dict3.count 获取字典元素个数
NSLog(@"%lu",dict3.count);
//遍历数组快速枚举
for (NSString *key in dict3) {
NSLog(@"key=%@,value=%@",key,[dict3 objectForKey:key]);
}
//bock 注意[{ }]格式
[dict3 enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop)
{
NSLog(@"%@%@",key,obj);
}];
NSDictionary *dictionary=
@{@"zhangsan":@"zs",@"ww":@"wangwu",@"xr":@"xiaoruo"};
//快速获取k值对应的value值
NSLog(@"%@",dictionary[@"ww"]);
bool b= [dictionary writeToFile:@"/Users/mac/Desktop/123.plist" atomically:YES];
if (b) {
NSLog(@"写入成功");
}
NSDictionary *d2=[NSDictionary dictionaryWithContentsOfFile:@"/Users/mac/Desktop/123.plist"];
NSLog(@"%@",d2);
//将字典里的元素存放到数组
// NSArray *a=dictionary[@"xr"];
// NSLog(@"%@",[a lastObject]);
}

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#import <Foundation/Foundation.h>
int main(int argc, const char * argv[]) {
@autoreleasepool {
//可变字典才可以改xxxx
// NSDictionary *dict=[NSDictionary dictionaryWithObjectsAndKeys:@"1":@"!!!",@"2":@"222", nil];
NSMutableDictionary *dict=[NSMutableDictionary dictionary];
//增加
[dict setValue:@"333" forKey:@"3"];
[dict setValue:@"312" forKey:@"2"];
[dict setValue:@"3da3" forKey:@"1"];
NSLog(@"%@",dict);
//修改
[dict setObject:@"222" forKey:@"3"];
NSLog(@"%@",dict);
// 查找 allKeys显示所有k
NSArray *arr= [dict allKeys];
if ([arr containsObject:@"1"]) {
NSLog(@"已找到");
}
}
return 0;
}

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