预期的表达错误

Question

此Expected expression错误对此代码行的含义是什么：

[super setNilValueForKey:key];

代码：

#import "Person.h"

@implementation Person

- (id) init
{
    self = [super init];
    expectedRaise = 5.0;
    personName = @"New Person";
    return self;    
}

- (void)dealloc
{
    [personName release];
    [super dealloc];
}

- (void)setNilValueForKey:(NSString *)key
{
    if ([key isEqual:@"expectedRaise"])
    {
        [self setExpectedRaise:0.0];
    }
    else
    {
        [super setNilValueForKey:key];
    }
}
@synthesize personName;
@synthesize expectedRaise;

@end

·H：

#import <Foundation/Foundation.h>

@interface Person : NSObject
{
    NSString *personName;
    float expectedRaise;
}

@property (readwrite, copy) NSString *personName;
@property (readwrite) float expectedRaise;

@end

Answer 1

如果你真的有

[super setNilValueForKey:<#key#>];

在您的代码中，解决方案应该像

一样简单

[super setNilValueForKey:key];

Answer 2

isEqual是错误的方法，因为我想比较字符串值isEqualToString是正确的。

 - (void)setNilValueForKey:(NSString *)key
    {
        if ([key isEqualToString:@"expectedRaise"])
        {
            [self setExpectedRaise:0.0];
        }
        else
        {
            [super setNilValueForKey:key];
        }
    }