ios随机生成4个字符串

来源：互联网发布：淘宝店铺怎么增加分类编辑：程序博客网时间：2024/06/05 19:33

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
- (NSString*)shuffledAlphabet {
    NSString*alphabet = @"abcdefghijklmnopqrstuvwxyz";
     
    // Get the characters into a C array for efficient shuffling
    NSUIntegernumberOfCharacters = [alphabet length];
    unichar *characters = calloc(numberOfCharacters,sizeof(unichar));
    [alphabet getCharacters:characters range:NSMakeRange(0, numberOfCharacters)];
     
    // Perform a Fisher-Yates shuffle
    for(NSUIntegeri = 0; i < numberOfCharacters; ++i) {
        NSUIntegerj = (arc4random_uniform(numberOfCharacters - i) + i);
        unichar c = characters[i];
        characters[i] = characters[j];
        characters[j] = c;
    }
     
    // Turn the result back into a string
    NSString*result = [NSStringstringWithCharacters:characters length:numberOfCharacters];
    free(characters);
     
    NSString*theFourString = [result substringToIndex:4];
     
     
    returntheFourString;
}

阅读全文

0 0