[英]No visible @interface for 'GADUNativeCustomTemplateAd' error
[英]No visible interface error
我已注释掉我模型的实现文件中的错误。 我该怎么做才能解决此问题?
提前致谢。
#import "CalculatorBrain.h"
@interface CalculatorBrain()
@property (nonatomic, strong) NSMutableSet *operandStack;
@end
@implementation CalculatorBrain
@synthesize operandStack = _operandStack;
- (NSMutableArray *)operandStack
{
if (!_operandStack) {
_operandStack = [[NSMutableArray alloc] init];
}
return _operandStack;
}
-(void)pushOperand:(double)operand
{
NSNumber *operandObject = [NSNumber numberWithDouble:operand];
[self.operandStack addObject:operandObject];
}
- (double)popOperand
{
NSNumber *operandObject = [self.operandStack lastObject]; // No visible interface for 'NSMutableSet' declares the selector 'lastObject'
if(operandObject) [self.operandStack removeLastObject]; // No visible interface for 'NSMutableSet' declares the selector 'removeLastObject'
return [operandObject doubleValue];
}
- (double)performOperation:(NSString *)operation
{
double result = 0;
if([operation isEqualToString:@"+"]) {
result = [self popOperand] + [self popOperand];
} else if ([@"*" isEqualToString:operation]) {
result = [self popOperand] * [self popOperand];
} else if ([operation isEqualToString:@"-"]) {
double subtrahend = [self popOperand];
result = [self popOperand] - subtrahend;
} else if ([operation isEqualToString:@"/"]) {
double divisor = [self popOperand];
if (divisor)result = [self popOperand] / divisor;
}
[self pushOperand:result];
return result;
}
@end
您已经将您的operandStack
属性声明为NSMutableSet
,但是应该将其声明为NSMutableArray
:
@property (nonatomic, strong) NSMutableArray *operandStack;
您正在尝试获取NSSet
的“最后一个对象”-这是不可能的,因为集合是无序的。 NSMutableSet不存在lastObject
方法。
您可能想尝试使用NSMutableArray。
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