objective-c 日期

NSDate

NSDate *date = [NSDate new];  //默认为当前日期
//NSDate *date = [NSDate date];  //调用date方法也可以
NSLog(@"print date is %@",date);

dateFormat 格式化输出

   NSDateFormatter *formatter = [NSDateFormatter new];
        
   formatter.dateFormat = @"yyyy-MM-dd HH:mm:ss z";
        
   //[formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss z"];
   
   NSString *str = [formatter stringFromDate:date];
        
   NSLog(@"print date is %@",str);

dateFormat 反格式化

NSString *dateString = @"2023-04-02 11:33:04";
        
NSDateFormatter *formatter = [NSDateFormatter new];
        
[formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
        
NSDate *date = [formatter dateFromString:dateString];
        
NSLog(@"print date is %@",date);