生成随机数
代码:
#import <Foundation/Foundation.h> int main (int argc, const char * argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; //Objective-C 没有提供相关的函数生成随机数,不过C供了rand(), srand(), random(), srandom(), arc4random()几个函数。 //其中arc4random()不用seed //生成0到100的随机数 int x = arc4random() % 100; NSLog(@"0~100 = %@",[NSNumber numberWithInt:x]); //生成500到1000的随机数 int y = (arc4random() % 501) + 500; NSLog(@"500~1000 = %@",[NSNumber numberWithInt:y]); [pool drain]; return 0; }
结果:
[Switching to process 1637 thread 0x0] 2011-05-10 09:54:03.008 demo02[1637:903] 0~100 = 6 2011-05-10 09:54:03.011 demo02[1637:903] 500~1000 = 837