1)、arc4random() 比较精确不需要生成随即种子 使用方法 : 通过arc4random() 获取0到x-1之间的整数的代码如下: int value = arc4random() % x; 获取1到x之间的整数的代码如下: int value = (arc4random 个人来说我首选arc4random() ,原因就是它是一个真正的伪随机算法,而且范围是rand()的两倍。 num2 { int startVal = num1*10000; int endVal = num2*10000; int randomValue = startVal +(arc4random
age :Int = 0 //初始化随机姓名和年龄 override init() { name = String(format: "%c%c%c", 65 + arc4random ()', 65 + arc4random()', 65 + arc4random()') age = Int( arc4random() % 10 + 18 ) }
int i = arc4random() % 5 ; 注: rand()和random()实际并不是一个真正的伪随机数发生器,在使用之前需要先初始化随机种子,否则每次生成的随机数一样。 arc4random() 是一个真正的伪随机算法,不需要生成随机种子,因为第一次调用的时候就会自动生成。而且范围是rand()的两倍。 精确度比较:arc4random() > random() > rand()。 常用方法:arc4random 1、获取一个随机整数范围在:[0,100)包括0,不包括100 int x= arc4random() % 100; 2、 获取一个随机数范围在:[500,1000] :(int)fromto:(int)to { return (int)(from + (arc4random() % (to – from + 1))); }
unsigned)time(0)); //不加这句每次产生的随机数不变 int i = rand() % 5; srandom(time(0)); int i = random() % 5; int i = arc4random arc4random() 是一个真正的伪随机算法,不需要生成随机种子, 因为第一次调用的时候就会自动生成。而且范围是rand()的两倍。 在iPhone中,RAND_MAX是0x7fffffff (2147483647),而arc4random()返回的最大值则是 0x100000000 (4294967296)。 精确度比较:arc4random() > random() > rand()。 获取一个随机整数,范围在[from,to),包括from,不包括to -(int)getRandomNumber:(int)from to:(int)to { return (int)(from + (arc4random
dequeueReusableCellWithReuseIdentifier:@"cellid" forIndexPath:indexPath]; cell.backgroundColor = [UIColor colorWithRed:arc4random ()%255/255.0 green:arc4random()%255/255.0 blue:arc4random()%255/255.0 alpha:1]; return cell; } / ()%255/255.0 green:arc4random()%255/255.0 blue:arc4random()%255/255.0 alpha:1]; UICollectionViewCell dequeueReusableCellWithReuseIdentifier:@"cellid" forIndexPath:indexPath]; cell.backgroundColor = [UIColor colorWithRed:arc4random ()%255/255.0 green:arc4random()%255/255.0 blue:arc4random()%255/255.0 alpha:1]; return cell; } 效果如下
() % 256 / 256.0 green:arc4random() % 256 / 256.0 blue:arc4random() % 256 / 256.0 alpha:1.0]; #define kLineCount 6 #define kLineWidth 1.0 #define kCharCount 6 #define kFontSize [UIFont systemFontOfSize:arc4random ; //随机从数组中选取需要个数的字符串,拼接为验证码字符串 for (int i = 0; i < kCharCount; i++) { NSInteger index = arc4random () % (int)rect.size.width; pY = arc4random() % (int)rect.size.height; CGContextMoveToPoint( context, pX, pY); //设置线终点 pX = arc4random() % (int)rect.size.width; pY = arc4random
但是Objective-C并没有提供相关函数,好在C提供了rand(), srand(), random(), srandom(), arc4random()几个函数 // Get random number between 0 and 500 int x = arc4random() % 100; // Get random number between 500 and 1000 int y = ( arc4random() % 501) + 500); arc4random()的好处是不用seed ---- Previous 给TableView
self.view.layer addSublayer:_colorLayer]; } - (IBAction)changeColor:(UIButton *)sender{ CGFloat red = arc4random () % 255 / 255.0; CGFloat green = arc4random() % 255 / 255.0; CGFloat blue = arc4random() % 255 transform, M_PI_2); self.colorLayer.affineTransform = transform; }]; CGFloat red = arc4random () % 255 / 255.0; CGFloat green = arc4random() % 255 / 255.0; CGFloat blue = arc4random() % 255 () % 255 / 255.0; CGFloat green = arc4random() % 255 / 255.0; CGFloat blue = arc4random() % 255
dequeueReusableCellWithReuseIdentifier:_CELL forIndexPath:indexPath]; cell.backgroundColor = [UIColor colorWithRed:((arc4random ()%255)/255.0) green:((arc4random()%255)/255.0) blue:((arc4random()%255)/255.0) alpha:1.0f]; return collectionView cellForItemAtIndexPath:indexPath]; cell.backgroundColor = [UIColor colorWithRed:((arc4random ()%255)/255.0) green:((arc4random()%255)/255.0) blue:((arc4random()%255)/255.0) alpha:1.0f]; } //返回这个
//arc4random() 比较精确不需要生成随即种子 //通过arc4random() 获取0到x-1之间的整数的代码如下: int value = arc4random() % x; / /获取1到x之间的整数的代码如下: int value = (arc4random() % x) + 1; //CCRANDOM_0_1() cocos2d中使用 ,范围是[0,1] float
C语言随机函数rand() random() drand48() OC随机函数arc4random() arc4random_uniform() rand() // 生成m~n之间的随机整数 -(int isSranded) { isSranded = YES; srand48(time(0)); } return drand48(); } arc4random () // 生成m~n之间的随机整数 -(int)arc4randomFrom:(int)m to:(int)n{ return m + arc4random()%(n - m + 1); }
intValue] % 2 + 1]]]; //初始化金币的最终位置 coin.center = CGPointMake(CGRectGetMidX(self.view.frame) + arc4random ()%40 * (arc4random() %3 - 1) - 20, CGRectGetMidY(self.view.frame) - 20); coin.tag = [i intValue] coin.layer.position.x; //终点x CGFloat positionY = coin.layer.position.y; //终点y int fromX = arc4random UIScreen mainScreen].bounds.size.height + coin.frame.size.height; //y轴以屏幕高度为准 int fromY = arc4random /////////////////////////////////////////////////// //图像由大到小的变化动画 CGFloat from3DScale = 1 + arc4random
max_lineWidth = 5; float min_lineWidth = 1; int alpha_min = 10; int alpha_max = 200; int R = arc4random ()%255; int G = arc4random()%255; int B = arc4random()%255; int pointListCount = pointList.size(
UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath{ return CGSizeMake(arc4random dequeueReusableCellWithReuseIdentifier:@"cellID" forIndexPath:indexPath]; cell.backgroundColor = [UIColor colorWithRed:arc4random ()%255/255.0 green:arc4random()%255/255.0 blue:arc4random()%255/255.0 alpha:1]; return cell; } @end
()%256 / 255.0 green:arc4random()%256 / 255.0 blue:arc4random()%256/ 255.0 alpha:1.0]; } }]; [UIView ) { UIView *view = self.viewArray[6]; view.backgroundColor = [UIColor colorWithRed: arc4random ()%256 / 255.0 green:arc4random()%256 / 255.0 blue:arc4random()%256/ 255.0 alpha:1.0]; } }] UIView *view = self.viewArray[7]; view.backgroundColor = [UIColor colorWithRed: arc4random ()%256 / 255.0 green:arc4random()%256 / 255.0 blue:arc4random()%256/ 255.0 alpha:1.0]; } }]
UIView * view = [[UIView alloc]init]; view.backgroundColor = [UIColor colorWithRed:arc4random ()%255/255.0 green:arc4random()%255/255.0 blue:arc4random()%255/255.0 alpha:1]; [array addObject ()%255/255.0 green:arc4random()%255/255.0 blue:arc4random()%255/255.0 alpha:1]; [stackView addArrangedSubview UIView * view = [[UIView alloc]init]; view.backgroundColor = [UIColor colorWithRed:arc4random ()%255/255.0 green:arc4random()%255/255.0 blue:arc4random()%255/255.0 alpha:1]; float height
arc4random() 函数: 这个函数是 C 语言封装的一个比较智能的随机函数,我们只要调用这个函数,就会产生随机数,不用设置随机种子,而且用法很简单: int arc_rand = arc4random (); printf("arc_rand = %d\n", arc_rand); 产生随机 a-b的数值 arc4random() % (b - a + 1) + a; 本文共 670 个字数,平均阅读时长
//2.根据表Student中的键值,给NSManagedObject对象赋值 student.name = [NSString stringWithFormat:@"Mr-%d",arc4random ()%100]; student.age = arc4random()%20; student.sex = arc4random()%2 == 0 ? @"美女" : @"帅哥" ; student.height = arc4random()%180; student.number = arc4random()%100 //
UITouch *> *)touches withEvent:(UIEvent *)event { self.view.backgroundColor = [UIColor colorWithRed:arc4random ()%255/255.0 green:arc4random()%255/255.0 blue:arc4random()%255/255.0 alpha:1]; } // 录屏结束的回调 - (void
fulfill, FBLPromiseRejectBlock reject) { BOOL success = arc4random 对象后面挂一个then方法,表示这个Promise执行完毕之后,要继续执行的任务: [[[FBLPromise do:^id _Nullable{ BOOL success = arc4random NSString *> *)pay:(NSString *)payParam { return [FBLPromise do:^id _Nullable{ BOOL success = arc4random - (FBLPromise<NSString *> *)work1 { return [FBLPromise do:^id _Nullable{ BOOL success = arc4random (FBLPromise<NSNumber *> *)work2 { return [FBLPromise do:^id _Nullable{ BOOL success = arc4random