[OC Foundation框架

日期处理类

1. 定义
2. 时间间隔计算
3. 时间比较，返回其一
4. 时间格式化

void dateCreate()
{
    //date return current time
    NSDate *date = [NSDate date];
    NSLog(@"%@", date);
   
    //+ 10 sec
    date = [NSDate dateWithTimeIntervalSinceNow:10];
    NSLog(@"%@", date);
   
    //1970-1-1 00:00:00 + 10 sec
    date = [NSDate dateWithTimeIntervalSince1970:10];
    NSLog(@"%@", date);
   
    //Random future time?
    date = [NSDate distantFuture];
    NSLog(@"%@", date);
   
    date = [NSDate distantPast];
    NSLog(@"%@", date);
}
 
void dateUse()
{
    NSDate *date = [NSDate date];
    //NSTimeInterval is double
    NSTimeInterval i = [date timeIntervalSince1970];
    NSLog(@"%f", i);
}
 
void dateFormat()
{
    NSDate *date = [NSDate date];
    NSDateFormatter *f = [[NSDateFormatter alloc] init];
    f.dateFormat = @"yyyy-MMM-dd HH:mm:ss";
    NSString *s = [f stringFromDate:date];
    NSLog(@"1:%@", s);
   
    NSDate *d2 = [f dateFromString:@"2014-7月-29 22:12:12"];
    NSLog(@"2:%@",d2);
}

 

字符串、日期格式转换：

        // 17.将2013年05月05日转换为2013-05-05
        NSMutableString *str17 = @"2013年05月05日";
        NSDateFormatter *dateFormatter1 = [[NSDateFormatter alloc] init];
        dateFormatter1.dateFormat = @"yyyy年MM月dd日";
        NSDate *date1 = [dateFormatter1 dateFromString:str17];
        NSDateFormatter *dateFormatter2 = [[NSDateFormatter alloc] init];
        dateFormatter2.dateFormat = @"yyyy-MM-dd";
        NSString *str17_2 = [dateFormatter2 stringFromDate:date1];
        NSLog(@"题目17, 转换后的日期是%@", str17_2);