nsobject或者字典的类目中实现
- (NSDictionary *)dictForKey:(NSString *)key{
if (![self isKindOfClass:[NSDictionary class]] || !key.hasValue) {
return @{};
}else{
NSDictionary * dic = (NSDictionary *)self;
NSDictionary * value = [dic objectForKey:key];
if (!value || ![value isKindOfClass:[NSDictionary class]]) {
return @{};
}
return value;
}
}
- (NSArray *)arrForKey:(NSString *)key{
if (![self isKindOfClass:[NSDictionary class]] || !key.hasValue) {
return @[];
}else{
NSDictionary * dic = (NSDictionary *)self;
NSArray * value = [dic objectForKey:key];
if (!value || ![value isKindOfClass:[NSArray class]]) {
return @[];
}
return value;
}
}
- (NSString *)stringForKey:(NSString *)key{
if (![self isKindOfClass:[NSDictionary class]] || !key.hasValue) {
return @"";
}else{
NSDictionary * dic = (NSDictionary *)self;
NSString * value = [dic objectForKey:key];
if (!value || ![value isKindOfClass:[NSString class]]) {
if ([value isKindOfClass:[NSNumber class]])
{
return ((NSNumber *)value).stringValue;
}
return @"";
}
return value;
}
}
