NSDictionary创建
NSDictionary*dict = [NSDictionarydictionaryWithObject:@"aaa"forKey:@"name"];
NSString*name = [dictobjectForKey:@"name"];//把name作为键值
NSLog(@"%@",name);//不妨输出看看打印出的样子
NSDictionary*dict = [NSDictionarydictionaryWithObjects:@[@"aaa",@"20",@"1.7"]forKeys:@[@"name",@"age",@"height"]];
NSString*name = [dictobjectForKey:@"name"];
NSString*age = [dictobjectForKey:@"age"];
NSString*height = [dictobjectForKey:@"height"];
NSLog(@"%@,%@,%@",name,age,height);
输出：
{
age = 20;
height = "1.7";
name = aaa;
}
简写形式：
快速创建字典
NSDictionary*dict = @{@"name":@"aaa",@"age":@"30"};
NSLog(@"%@,%@",dict[@"name"],dict[@"age"]);
NSDictionary遍历
常规遍历
NSDictionary*dict = @{@"name":@"aaa",@"age":@"30",@"height":@"1.7"};
// 2.1如何获取字典中key和value的个数,在字典中key称之为键, value称之为值
for(inti = 0; i < dict.count; i++) {
//获取字典中所有的key
NSArray*keys = [dictallKeys];
//取出当前位置对应的key
NSString*key = keys[i];
NSString*value = dict[key];
NSLog(@"key = %@,value = %@",key,value);
}
使用OC中的增强for循环来遍历
for(NSString *keyindict) {
NSString *value = dict[key];
NSLog(@"key = %@,value = %@",key,value);
}
使用OC数组的迭代器来遍历
[dict enumerateKeysAndObjectsUsingBlock:^(id_Nonnullkey,id_Nonnullvalue,BOOL*_Nonnullstop) {
NSLog(@"key = %@,value = %@",key,value);
}];
字典排序
字典输出来的是无序的，按照key首字母英文单词排序
NSDictionary文件读写
字典文件写入
NSDictionary*dict = @{@"name":@"aaa",@"age":@"30",@"height":@"1.7"};
[dictwriteToFile:@"/Users/kobi/Desktop/abc.plist"atomically:YES];
字典文件读出
NSDictionary*newDict = [NSDictionary dictionaryWithContentsOfFile:@"/Users/kobi/Desktop/abc.plist"];
NSLog(@"%@",newDict);
NSMutableDictionary
增删改查
创建一个空的字典
NSMutableDictionary*dictM = [NSMutableDictionary dictionary];
添加键值
[dictMsetObject:@"lnj"forKey:@"name"];
NSLog(@"%@",dictM);
[dictMsetValuesForKeysWithDictionary:@{@"age":@"30",@"height":@"1.7"}];
NSLog(@"%@",dictM);
删除键值
[dictMremoveObjectForKey:@"name"];
NSLog(@"%@",dictM);
[dictMremoveObjectsForKeys:@[@"age",@"height"]];
NSLog(@"%@",dictM);
替换元素
[dictMsetObject:@"99"forKey:@"age"];
dictM[@"age"] =@"89";
NSLog(@"%@",dictM);
获取元素
NSLog(@"name = %@",dictM[@"name"]);
