判斷陣列中是否包含某個物件
阿新 • • 發佈:2018-12-31
要想比較需要重寫-isEqual:和-hash
當判斷anObject是否在當前的NSArray中的時候,是通過呼叫這個方法來判斷的,isEqual:本質是在比較兩個物件的hash值
@interface Person
@property NSString *name;
@property NSDate *birthday;
- (BOOL)isEqualToPerson:(Person *)person;
@end
@implementation Person
- (BOOL)isEqualToPerson:(Person *)person {
if (!person) {
return NO;
}
BOOL haveEqualNames = (!self.name && !person.name) || [self.name isEqualToString:person.name];
BOOL haveEqualBirthdays = (!self.birthday && !person.birthday) || [self.birthday isEqualToDate:person.birthday];
return haveEqualNames && haveEqualBirthdays;
}
#pragma mark - NSObject
- (BOOL)isEqual:(id)object {
if (self == object) {
return YES;
}
if (![object isKindOfClass:[Person class]]) {
return NO;
}
return [self isEqualToPerson:(Person *)object];
}
- (NSUInteger)hash {
return [self.name hash] ^ [self.birthday hash];
}
@interface Person
@property NSString *name;
@property NSDate *birthday;
- (BOOL)isEqualToPerson:(Person *)person;
@end
@implementation Person
- (BOOL)isEqualToPerson:(Person *)person {
if (!person) {
return NO;
}
BOOL haveEqualNames = (!self.name && !person.name) || [self.name isEqualToString:person.name];
BOOL haveEqualBirthdays = (!self.birthday && !person.birthday) || [self.birthday isEqualToDate:person.birthday];
return haveEqualNames && haveEqualBirthdays;
}
#pragma mark - NSObject
- (BOOL)isEqual:(id)object {
if (self == object) {
return YES;
}
if (![object isKindOfClass:[Person class]]) {
return NO;
}
return [self isEqualToPerson:(Person *)object];
}
- (NSUInteger)hash {
return [self.name hash] ^ [self.birthday hash];
}