Sum of array in swift 3

Let's say you have array of int and you want to total of all element.
Here is example,

        let ints = 1...10 // [1,2,3,4,5,6,7,8,9,10]
        print(ints.reduce(0, +))

After running this 2 lines of code you will get total of 1 to 10.

NSDateFormatter example

//get current time and date
let currentTime = NSDate()
let dateFormat = NSDateFormatter()
dateFormat.dateFormat = "yyyy/MM/dd HH:mm:ss"
print(dateFormat.stringFromDate(currentTime))

here is the chart which will be the most useful date field symbols

Format	Description	Example
"y"	A year with 1 digit.	1 AD -> "1" 42 AD -> "42" 2014 AD -> "2014"
"yy"	A year with exactly 2 digits. If less then it will padded with 0. It will be truncated to the tens digit if larger	1 AD -> "01" 42 AD -> "42" 2014 AD -> "14"
"yyy"	A year with at least 3 digits. If less then it will padded with 0.	1 AD -> "001" 42 AD -> "042" 2014 AD -> "2014"
"yyyy"	A year with at least 3 digits. If less then it will padded with 0.	1 AD -> "0001" 42 AD -> "0042" 2014 AD -> "2014"
"M"	A month with at least 1 digits.	June -> "6" December -> "12"
"MM"	A month with at least 2 digits. If less then it will padded with 0.	June -> "06" December -> "12"
"MMM"	Three letter month abbreviation	June -> "Jun" December -> "Dec"
"MMMM"	Full name of month	June -> "June" December -> "December"
"MMMMM"	One letter month abbreviation January, June and July are "J"	June -> "J" December -> "D"
"d"	A day with at least 1 digit	4 -> "4" 24 -> "24"
"dd"	A day with at least 2 digit. If less then it will padded with 0.	4 -> "04" 24 -> "24"
"E","EE" or "EEE"	3 letter day abbreviation of day name	Wednesday -> "Wed" Thursday -> "Thu"
"EEEE"	Full day name	Wednesday -> "Wednesday" Thursday -> "Thursday"
"EEEEE"	1 letter day abbreviation of day name. Teusday and Thursday are "T"	Wednesday -> "W" Thursday -> "T"
"EEEEEE"	2 letter day abbreviation of day name	Wednesday -> "We" Thursday -> "Th"
"a"	period of day (AM/PM)	7 PM -> "PM" 10 AM -> "AM"
"h"	12 hour based with at least 1 digit	7 PM -> "7" 10 AM -> "10"
"hh"	12 hour based with at least 2 digit. If less then it will padded with 0.	7 PM -> "07" 10 AM -> "10"
"H"	24 hour based with at least 1 digit	7 PM -> "19" 10 AM -> "10"
"HH"	24 hour based with at least 2 digit. If less then it will padded with 0.	7 PM -> "19" 9 AM -> "09"
"m"	A minute with at least 1 digit	40 -> "40" 1 -> "1"
"mm"	A minute with at least 2 digit. If less then it will padded with 0.	40 -> "40" 1 -> "01"
"s"	A second with at least 1 digit	40 -> "40" 1 -> "1"
"ss"	A second with at least 2 digit. If less then it will padded with 0.	40 -> "40" 1 -> "01"
"S"	A tenth place of fraction second	123 ms -> "1" 7 ms -> "0"
"SS"	A tenth and hundredths place of fractions second	123 ms -> "12" 7 ms -> "00"
"SSS"	A tenth, hundredths and thousandths place of fractions second	123 ms -> "123" 7 ms -> "007"