OC 入门实现登陆验证

#import <Foundation/Foundation.h>@interface CZLogin : NSObject{    char *_username;    char *_password;}-(BOOL)validateUserName:(NSString *)username andValidatePassword:(NSString *)password;@end@implementation CZLogin-(BOOL)validateUserName:(NSString *)username andValidatePassword:(NSString *)password{    if (username == nil || [username isEqualTo:@""] ) {        NSLog(@"username can be not null");        return NO;    }    if (password == nil || [password isEqualTo:@""] ) {        NSLog(@"password can be not null");        return NO;    }    if([username isEqualTo:@"admin"] && [password isEqualTo:@"admin"]){        NSLog(@"login success");        return YES;    }    return NO;}@endint main(int argc, const char * argv[]){    @autoreleasepool {        CZLogin *login = [CZLogin new];        [login validateUserName:@"admin" andValidatePassword:@"admin"];        NSLog(@"Hello, World!");    }    return 0;}