编辑代码

#import <Foundation/Foundation.h>

@interface ListNode : NSObject

@property (nonatomic) NSInteger value;
@property (nonatomic) ListNode *nextNode;

@end

@implementation ListNode

- (void)printfValue {
    printf("%s",[str UTF8String]);
}

@end

int main(int argc, char* argv[]) {
    NSString * str=@"Hello world!    - objc.jsrun.net";
    printf("%s",[str UTF8String]);
    return 0;
}