编辑代码

#import <Foundation/Foundation.h>

@interface ListNode : NSObject

@property (nonatomic, assign) NSInteger value;
@property (nonatomic) ListNode *next;

@end

@implementation ListNode

- (void)test {
    printf("aaa");
}

- (instancetype)initWithNumber:(NSInteger)number {
    self = [super init];
    if (self) {
        self.value = number;
    }
    return self;
}

@end

int main(int argc, char* argv[]) {

    ListNode *node = [[ListNode alloc] initWithNumber:3];
    [node test];

    return 0;
}