指针和整数之间的比较

Question

我只是在学习Cocoa(来自C#),我发现一个看似非常简单的奇怪错误.(charsSinceLastUpdate >= 36)

#import "CSMainController.h"

@implementation CSMainController
//global vars
int *charsSinceLastUpdate = 0;
NSString *myString = @"Hello world";
//

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
...
}

//other functions
- (void)textDidChange:(NSNotification *)aNotification {
    NSLog(@"charsSinceLastUpdate=%i",charsSinceLastUpdate);
    if (charsSinceLastUpdate>=36) { // <- THIS line returns the error: Comparison between pointer and integer
        charsSinceLastUpdate=0;
        [statusText setStringValue:@"Will save now!"];
    } else {
        charsSinceLastUpdate++;
        [statusText setStringValue:@"Not saving"];
    }

}

//my functions
- (void)showNetworkErrorAlert:(BOOL)showContinueWithoutSavingOption {
...
}
//

@end

任何帮助将不胜感激,谢谢!

Answer 1

在你的代码,charsSinceLastUpdate是一个指针,你需要定义它没有的*:

int charsSinceLastUpdate = 0;

当然,除非您打算将其定义为指针,在这种情况下,您需要使用解除引用运算符来检索它指向的值,如下所示:

if(*charsSinceLastUpdate >= 36) {
   //...
}