iOS 检查指定日期是否在当前日期之前

- (BOOL)checkProductDate: (NSString *)tempDate {
    
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    
    [dateFormatter setDateFormat:@"yyyy-MM-dd"];
    
    NSDate *date = [dateFormatter dateFromString:tempDate];
    
    // 判断是否大于当前时间
    if ([date earlierDate:[NSDate date]] != date) {
        
        return true;
    } else {
        
        return false;
    }
    
}