Develop
2013.10.31 16:51
[ios] Random Thoughts: Rand() vs. arc4random()
조회 수 68050 댓글 0
랜덤함수 사용시..
iOS
There are several built-in randomizers on the iPhone, and most people's first thought is to use rand() after seeding it by calling
srandom(time(NULL));
But... rand() is really not a very good PRNG. random() is a little better, but still less then ideal. Fortunately, these are not the only ones available on the iPhone. Personally, I like arc4random() because it's a decent pseudo-random algorithm and has twice the range or rand().
On the iPhone, RAND_MAX is 0x7fffffff (2147483647), while arc4random() will return a maximum value of 0x100000000 (4294967296), giving much more precision. You also don't need to seed arc4random(), as the first call to it automatically seeds it.
결론은 arc4random() 을 사용하자.
[출처] http://iphonedevelopment.blogspot.com/2008/10/random-thoughts-rand-vs-arc4random.html
-
[ios] Swift 4 Singleton inheritance
-
[ios] Swift 4 Dictionary 사용하기
-
[ios] StoryBoard(xib) 없이 프로젝트 만들기
-
[ios] Start developing your navigation app for CarPlay without enrollment
-
[ios] SQLite 사용하기(튜토리얼) + 샘플코드
-
[ios] Sprite Kit & 사운드 재생시 백그라운드 진입시 앱이 비정상적으로 종료됨
-
[ios] SBCampanion App 초안
-
[ios] Requesting Location Permissions in iOS
-
[ios] Random Thoughts: Rand() vs. arc4random()
-
[ios] Pod 특정 버전 설치하고 사용하기
-
[ios] PHP로 APNS 프로바이더~
-
[ios] Objective-C에서 형식이 있는 문자열(Format Strings)에 사용할 수 있는 토큰들(Tokens)