It is a common task to generate a random n char string (alphanumeric string). It can be solved the following way. First, we generate an alphabet, that has m chars. Then in a cycle we generate random indexes from 0 to (m-1) and take a char from alphabet with random index.
|
1 2 3 4 5 6 7 8 9 10 |
NSString *alphabet = @"abcdefghijklmnopqrstuvwxyz \ ABCDEFGHIJKLMNOPQRSTUVWXZY0123456789"; NSMutableString *s = [NSMutableString stringWithCapacity:20]; for (NSUInteger i = 0U; i < 20; i++) { u_int32_t r = arc4random() % [alphabet length]; unichar c = [alphabet characterAtIndex:r]; [s appendFormat:@"%C", c]; } NSLog(@"%@", s); NSString *key = s; |
Inspired by this post