版本
Xcode 8.2.1
一、不可变字典NSDictionary
字典就是，key和value成对相对应地存入dictionary。key为字符串，value为所有对象Object，可以是string、array等等。
//创建:value1,key1,value2,key2...,(key和value成对出现)
//value:OC的任何对象都可以，
NSDictionary *dic11 = [NSDictionary dictionaryWithObjectsAndKeys:@"aabbb",@"1",@"dddeee",@"2",nil];
NSLog(@"dic = %@",dic11);
//key1:value1,key2:value2...
//@{}只能用于创建不可变字典
NSDictionary *dic1 = @{@"One":@"11",@"Two":@"22",@"Three":@"22"};
NSLog(@"dic1 = %@",dic1);
//通过key值访问value值
NSString *strDic = [dic1 valueForKey:@"Two"];
NSLog(@"strDic = %@",strDic);
//访问value,dic [key]
NSString *strDic1 = dic1[@"Two"];
NSLog(@"strDic1 = %@",strDic1);
//遍历字典，遍历key值
NSArray *keyArr = [dic1 allKeys];
for(NSString *keyin keyArr) {
NSLog(@"key = %@",key);
}
//通过value,获取具有相同value的key array
NSArray *keyArr1 = [dic1 allKeysForObject:@"22"];
//遍历Value值,返回所有的Value值
NSArray *valArr = [dic1 allValues];
for(id valuein valArr) {
NSLog(@"value = %@",value);
}
//默认遍历key值
for(id objin dic1) {
NSLog(@"obj = %@",dic1[obj]);
}
NSArray栗子：
先创建一个plist文件,并取名dict3，等下我们将通过这个名字来查找内容：
1.jpg
2.jpg
填入key和value：
3.jpg
然后来到main方法：
int main(int argc, char * argv[]) {
//@{}只能用于创建不可变字典(注意：先key后value)
NSDictionary *dict1 = @{@"role":@"Invincible Eastern",@"age":@"30",@"sex":@"male&female"};
NSLog(@"%@",dict1);
//value:OC的任何对象都可以(注意：先value后key)
NSDictionary *dict2 = [NSDictionary dictionaryWithObjectsAndKeys:@"the monkey king",@"role",@"500",@"age",@"male",@"sex", nil];
NSLog(@"%@",dict2);
//查plist文件
NSDictionary *dict3 = [NSDictionary dictionaryWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"dict3" ofType:@"plist" ]];
NSLog(@"%@",dict3);
NSLog(@"%@",dict3[@"role"]);
//访问value
NSLog(@"%@",[dict2 valueForKey:@"age"]);
NSLog(@"%@",[dict2 objectForKey:@"age"]);
NSLog(@"%@",dict2[@"age"]);
//遍历value
NSArray *valArr = [dict2 allValues];
for(id value in valArr){
NSLog(@"value = %@",value);
}
//获取具有相同value的key array
NSArray *keyArr1 = [dict2 allKeysForObject:@"500"];
NSLog(@"500的key为%@",keyArr1);
//遍历key
NSArray *keyArr2 = [dict2 allKeys];
for(id value in keyArr2){
NSLog(@"key = %@",value);
}
//默认遍历keu
for(id value in dict2){
NSLog(@"obj = %@",dict2[value]);
}
}
输出结果:
二、可变字典NSMutableDictionary
//实例化一个空的可变字典
NSMutableDictionary *dic2 = [NSMutableDictionary dictionary];
// NSMutableDictionary *dic2 = [[NSMutableDictionary alloc]init];
//通过一个数组实例化一个可变字典
NSMutableDictionary *dic3 = [NSMutableDictionary dictionaryWithObjects:@[@"1",@"2",@"3"] forKeys:@[@"One",@"Three",@"Three"]];
NSLog(@"dic3 = %@",dic3);
//添加元素(当字典内不存在此key值)
[dic3 setObject:@"4" forKey:@"Four"];
//修改value值(当字典内存在此key值)
[dic3 setObject:@"11" forKey:@"One"];
//通过key值获取value值
NSString *rstr = [dic3 valueForKey:@"Two"];//dic3[@"Two"];
//删除，删除键值对
[dic3 removeObjectForKey:@"One"];
//删除所有数组中含有的key值的键值对
[dic3 removeObjectsForKeys:@[@"Four",@"Three"]];
//删除所有键值对
[dic3 removeAllObjects];
NSMutableDictionary栗子：
int main(int argc, char * argv[]) {
//实例化一个可变字典
NSMutableDictionary *dic1 = [NSMutableDictionary dictionary];
//NSMutableDictionary *dic1 = [[NSMutableDictionary alloc]init];
NSLog(@"dic1 = %@",dic1);
//通过一个数组实例化一个可变字典
NSMutableDictionary *dic2 = [NSMutableDictionary dictionaryWithObjects:@[@"Invincible Eastem",@"30"] forKeys:@[@"role",@"age"]];
NSLog(@"dic2 = %@",dic2);
//添加元素(当字典内不存在此key值)
[dic2 setObject:@"male" forKey:@"sex"];
NSLog(@"sex = %@",dic2);
//修改value值(当字典内存在此key值)
[dic2 setObject:@"female" forKey:@"sex"];
NSLog(@"sex = %@",dic2);
//通过key值获取value值
NSLog(@"sex = %@",[dic2 valueForKey:@"sex"]);
NSLog(@"sex = %@",dic2[@"sex"]);
//删除键值对
[dic2 removeObjectForKey:@"role"];
[dic2 removeObjectsForKeys:@[@"role",@"age"]];
//删除所有键值对
[dic2 removeAllObjects];
NSLog(@"sex = %@",dic2);
}
输出结果:
