Double to float

I found in APIs, there is a method: floatValue() to transfer double to float.But when I wrote the following code and compiled it, the error is:
myjava.java:437: double cannot be dereferenced
float ba=aa.floatValue();
program:
double aa=4;
float ba=aa.floatValue();
What's the problem in my program?
Thanks

That does not work because the floatValue() method exists in the Double wrapper class and not for the double primitive type. You should try either:
double aa = 4;
Double d = new Double(aa);
float ba = d.floatValue();or
double aa = 4;
float ba = (float)aa;

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Casting arrays from double to float

Hi, wonder if anyone can help.
I have a method of a class that creates two double arrays (the value pointed to is a double type)
x[][]
y[][]
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I need to convert String data to Double or Float , please help me about it. Thank you very muh!
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I found it but do not know if it is ok
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may be it can be!!!
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I added the (float) after the = in both and it fixed the top and not the bottom. "cant convert double to float" (as well as the answer to this, if somone could correct my terminology as well it would be appretiated. thanks in advance)
float torontoF = (float)(torontoC * 1.8) + 32;
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Reposted and answered at:
http://forum.java.sun.com/thread.jspa?threadID=5219089
Do not reply here.

Cannot explicit convert double.MaxValue/double.MinValue/float.MaxValue/float.MinValue to decimal

I'm try set double.MaxValue/double.MinValue/float.MaxValue/float.MinValue to NumericUpDown's Maximun/Minimum
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but variable and constant's explicit conversion is OK.
can anyone tell me why?
the screenshot is in below
http://i.imgur.com/woZXr0i.png

yes, your right!
I has been tried
If I assign it(MinValue/MaxValue) to a variable first and then explicit convert to a decimal
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Converting double to float

This problem only occurs when dealing with large numbers or numbers with a lot of fraction digits.
Here is an example:
double d = 7.1E9;
float f1 = (float)d;
float f2 = new Float(d).floatValue();
System.out.println( d + " " + f1 + " " + f2);
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Any ideas?
Thanks.
Igor.

float is only 32 bit while double is 64 bit, so you can easily get differences like that.
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Viewing only x number of digits for double or float

I was wondering if I had a float or a double, and lets say I didn't want to see all those decimal places, is there a way for me to limit the number of decimal places that is outputted to like 3 or 4 instead of 10? Thanks for the help.

oh...
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How can i convert a double to float

double gallons;
double startOdometer;
double endOdometer;
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You would use a cast.
double d = 1.4;
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My colleaque found an interesting behaviour with Java debugger. I have made some tests and here are the results:
Test code:
double dNum = 43.680659;
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I managed to find bug report of this issue:
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6807341
Information:
Bug ID : 6807341
Synopsis : JDWP: float value reported incorrectly
Category : java:debugger
State : 3-Accepted, bug
Priority : 4-Low
Submit Date: 19-FEB-2009

Help! double to float

How can I change a double to a float?

Hi,
You can just cast the float as a double:
double d = 123.4;
float f = (float) d;
a double has better precision so you may lose some precision when casting to a float.
chris.

Java dont know subtract double or float?!!!

The next simple java program print out Result: 6.999999999999999 when
it should be 7. What is the reason? (i try with float 14.89 7.89 and other variations and the result is incorrect too).
import java.io.*;
public class subtract{
public static void main(String argv[]){
double n1 = 14.87;
double n2 = 7.87;
double result = n1 - n2;
System.out.println("Result: "+result);
}

In my opinion the complexity of the internal
operations should be transparent for the programmer.
What i do expect is that the result of the trivial
mathematical operations be exact. For example my
cassio calculator do the 14.87-7.87=7 without error
and java do not (the windows calculator give me the
correct result, and excel too for example). How can i
use a double in java if i know that it is not exact?Java also gives a "correct" result if you round the numbers.
Remember that calculators are applications. They're written in some programming languages that treat floating point operations just like Java does. But the programmer has applied rounding before any result is displayed. When writing an application in Java you are that programmer.

Double into Float

Hey all,
Ive got a Double and I want to convert it to a Float and I want to check its within the IEEE 754 standards of the highest value you can have and lowest...
But I can't parse it, as Ive found out and .floatValue() doesn't throw an error as im aware, So I was wondering if you had any ideas
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or may need something like this, I'm not sure:
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Int varialbe being automatically promoted to double or float?

Hi everyone!
Normally, when a int is initialized (given) a single or double precision value, the compiler will complaint...
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But why is it that the method Integer.parseInt()
doesnt throw NumberformatExceptions when I input a
single or double precision value in a form of
string...It certainly should, and I just ran your code, entered the value "1.1", and a NullPointerException was thrown, resulting in my seeing the "Please input an integer!" message. If that doesn't happen for you, then you probably have a bug in your JDK.
Perhaps the following code is easier to follow, and it certainly demonstrates that Integer.parseInt throws a NullPointerException when the value "1.1" is entered:
public class Test {
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What is the difference btwn double and floating data type?

is it going to affect the computation?

What is the difference btwn J2SDK and J2EEhttp://java.sun.com/j2se/index.jsp
http://java.sun.com/j2ee/index.jsp

Double to float

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