how to get current date?

[Ekim]

I'm not quite familiar with the Java language, and therefore I have some
(assumed to be simple) questions.

How can I get the current systemdate in the format "dd-mm-yyyy".
I've already looked up in the API, and figured out that it can be done with
the "Date"-Class. Anyway I was not able to manage it.

My 2nd problem concerns rounding a double-number. I want to round a number
like "40.745043" to "40.75", so that it is rounded to 2 digits after the
decimal point.

I hope someone can help me answer those questions,

thx in advance,
ekim!

 

[TechBookReport]

I'm not quite familiar with the Java language, and therefore I have some
(assumed to be simple) questions.

How can I get the current systemdate in the format "dd-mm-yyyy".
I've already looked up in the API, and figured out that it can be done with
the "Date"-Class. Anyway I was not able to manage it.

My 2nd problem concerns rounding a double-number. I want to round a number
like "40.745043" to "40.75", so that it is rounded to 2 digits after the
decimal point.

I hope someone can help me answer those questions,

thx in advance,
ekim!

If you only want to round the number for display purpses then look at the
DecimalFormat class.

 

[Andrew Thompson]

I'm not quite familiar with the Java language, and therefore I have
some (assumed to be simple) questions.

For simple answers..
http://groups.google.com.au/groups?group=comp.lang.java.help

 

[Thomas Weidenfeller]

I'm not quite familiar with the Java language, and therefore I have some
(assumed to be simple) questions.

Consider posting your beginner's questions to comp.lang.java.help.

How can I get the current systemdate in the format "dd-mm-yyyy".
I've already looked up in the API, and figured out that it can be done with
the "Date"-Class. Anyway I was not able to manage it.
SimpleDateFormat

My 2nd problem concerns rounding a double-number. I want to round a number
like "40.745043" to "40.75", so that it is rounded to 2 digits after the
decimal point.

DecimalFormat.

Both in the java.text package.

/Thomas

 

[KD]

Hi

Question 1

import java.util.*

Date date = new Date();
// Keep the MM upper case
DateFormat df = new SimpleDateFormat("dd-MM-yyyy");
String formattedDate = df.format(date);

Question 2

If I remember correctly.

BigDecimal num = new BigDecimal("40.745043");
// You have to set this immediately. BigDecimal objects can never be
// changed - they are immutable
String myNewNum = num.setScale(2, BigDecimal.ROUND_UP).toString();

Good Luck
-Karim

 

[Chris Smith]

Hi Ekim,

Here's some more detail on your second problem.

My 2nd problem concerns rounding a double-number. I want to round a number
like "40.745043" to "40.75", so that it is rounded to 2 digits after the
decimal point.

The 'double' data type contains binary floating-point numbers rather
than decimal floating-point numbers. While 40.75 does happen to be
directly representable as a binary floating-point value (.01), the
general case of rounding a binary floating-point number to two decimal
digits is not even possible, since the floating-point number often won't
be able to exactly represent that value.

Depending on your application, though, there are solutions. For
example:

1. If this is just for display purposes, then you can use DecimalFormat
to get a rounded String. That works because the target type is String,
not double.

2. For intermediate results that need to be rounded (as required, for
example, in a number of financial calculations), a better choice is
often the BigDecimal class or a fixed-point representation using an int
(or long) and a constant factor -- for example, the integer 12345 might
be used to represent $123.45.

--
www.designacourse.com
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MindIQ Corporation