生成100个 "20180520" 这样的时间字符串 写入txt文件

主要想记录一下
 . 写NSString 到txt
. 数组的去重
. 数组的截取
. 数组分割

代码如下：

NSString *year = @"2018";

NSArray *momth = @[@"05",@"06",@"07",@"08",@"09",@"10",@"11",@"12"];

NSArray *day = @[@"01",@"02",@"03",@"04",@"05",@"06",@"07",@"08",@"09",@"10",@"11",@"12",@"13",@"14",@"15",@"16",@"17",@"18",@"19",@"20",@"21",@"22",@"23",@"24",@"25",@"26",@"27",@"28",@"29",@"30",@"31"];

NSMutableArray *dateStrArr = [NSMutableArray array];

for (int i = 0 ; i < 200; i++) {

NSString *momthStr = momth[arc4random()%momth.count];

NSString *dayStr = day[arc4random()%day.count];

if ([momthStr isEqualToString:@"02"] && [dayStr integerValue] > 28) {

continue;

}

//NSLog(@"%@%@%@",year,momthStr,dayStr);

NSString *dateStr = [NSString stringWithFormat:@"%@%@%@",year,momthStr,dayStr];

[dateStrArr addObject:dateStr];

//dateStr = [NSString stringWithFormat:@"\n%@",dateStr];

}

//去重

NSArray *result = [dateStrArr valueForKeyPath:@"@distinctUnionOfObjects.self"];

NSLog(@"去重1之后 =  %d",result.count);

//选100个

NSArray *finalArr = [result subarrayWithRange:NSMakeRange(0, 100)];

NSLog(@"去重1之后 =  %d",finalArr.count);

NSString *final = [finalArr componentsJoinedByString:@"\n"];

//NSLog(@"%@",final);

//NSFileHandle文件

//1.创建文件

NSFileManager *fm = [NSFileManager defaultManager];

//NSString *str = @"this is a test.\n 666";

NSData *data = [final dataUsingEncoding:NSUTF8StringEncoding];

[fm createFileAtPath:@"/Users/liuwei/Desktop/date2.txt" contents:data attributes:nil];