Formatting

Question 1

How do we format date or time?

Answer 1

Using DateTimeFormatter

Question 2

How can we set format of date or time using DateTimeFormatter?

Answer 2

DateTimeFormatter.ofPattern() or predefined DateTimeFormatter.ISO_LOCAL_TIME, DateTimeFormatter.ISO_LOCAL_DATE, DateTimeFormatter.ISO_LOCAL_DATE_TIME

Question 3

What is potential pitfall when using predefined “ISO” values?

Answer 3

Mix of date instead of time, and vice versa

Question 4

How do we use DateTimeFormatter on LocalDateTime

Answer 4

dateTime.format(DateTimeFormatter.ofPattern(“”))

Question 5

What letters are used in date time patterns?

Answer 5

m, M, h, s, d, M, a

Question 6

How do we format decimal numbers?

Answer 6

Using DecimalFormat

Question 7

What is the difference between 0 and # in DecimalFormat pattern?

Answer 7

Values at # are omitted if missing, 0 are not - it shows 0

Question 8

How do we format number using DecimalFormat ?

Answer 8

new DecimalFormat(“###.##”).format(number)

Question 9

What class does DecimalFormat extend?

Answer 9

NumberFormat