# precision « double « Java Data Type Q&A

### 1. Retain precision with Doubles in java    stackoverflow.com

``````public class doublePrecision {

public static void main(String[] args) {
double total = 0;
total += 5.6;
total += 5.8;
System.out.println(total);

}
``````
} Which returns
``````11.399999999999
``````
Okay clarifying the question a bit, how would i get ...

### 2. Java: Doing one's own data type? (eg. long long double?)    stackoverflow.com

I'm just pondering about whether or not it's possible to create one's own data type? So if you need more precision, that's not supported by one of the basic types, you could ...

### 3. How to read a double value with a certain precision    stackoverflow.com

How to read a double value from a String with a certain precision (say 4) assuming the string contains something like "10.1234" using this api

### 4. Displaying doubles to a certain precision in java    stackoverflow.com

I am currently writing a calculator application. I know that a double is not the best choice for good math. Most of the functions in the application have great precision but ...

### 5. Accuracy of double precision multiplication in java?    stackoverflow.com

What is the guaranteed accuracy of multiplication operator for double values in java? For example, 2.2 * 100 is 220.00000000000003, but 220 is a double number. 220.00000000000003 is the next ...

### 6. Precision in double    stackoverflow.com

I've got problem with precision in java. I have to calculate:

``````a * b -c, where:
a = 5.454E14
b = 3.646E-40
c = 2.3
``````
The score is `-2.3`. How I can solve it?
I don't ...

### 7. Higher precision doubles and trigonometric functions in Java    stackoverflow.com

According to IEEE the following doubles exist:

``````                Mantissa   Exponent
double 64bit:   ...``````

### 8. Why is arbitrary precision in double literals allowed in Java?    stackoverflow.com

I just learned from Peter Lawreys post that this is valid expression, and evaluates to `true`.

``````333333333333333.33d == 333333333333333.3d
``````
My question is, why is it allowed to have double literals which can't ...

### 9. Why do bean validation Min/Max constraints not support the double type?    stackoverflow.com

Could somebody please explain to me why the JPA supports the `double` type as a field type, but the bean validation constaints in `javax.validation.constraints` (i.e. @Min/@Max) do ...

### 10. Double number's multiplication with out precision and commas    stackoverflow.com

i have an array, a double array like...

``````Double my_array = new Double[] {6272640.0, 43560.0, 4840.0, 0.0015625, 4046856422.400000095, 40468564.223999999, 4046.856422400, 0.004046856, 1.0, 0.404685642};
``````
and in my program i want to multiply each of ...

### 11. double precision in JAVA    stackoverflow.com

I have to round off my result to the nearest fo 0.05 ie(6.34 to 6.35 and 6.37 to 6.4) So I created myRound function. ...

### 12. Double precision    coderanch.com

If you create a BigDecimal object from your double value, then you can set the scale (2) and choose your rounding method (looks like you want ROUND_DOWN or ROUND_FLOOR). After that, you can return to a type double if you like. This might be all you need, but suppose the result is 49.9 and you want to display a zero in ...

### 13. How to covert a String value to double without loosing the precision    coderanch.com

Hi, How can I convert a String value "106.4000" to a double, without loosing the precisions after 4 ? If I use, double dbl = Double.parseDouble("106.4000"); I am getting 106.4 only. But I need the exact string value as double. So please help me to do this. Thanks in advance... regards, Nishad P

### 14. Single & double Precision    coderanch.com

Hi, Sunanda! The single and double precision refer to the IEEE 754-1985 standard. For Java the following is true: single prec -> 32 bits -> Min = 1.43e-45 -> Max = 3.4e38 Double prec -> 64 bits -> Min = 4.942-324 -> Max = 1.8e308 As you can see, double precision can hold much larger values then the single precision. You ...

### 15. double precision?    coderanch.com

Hello, I am doing extensive calculations in my project which involves the use of "double" variable type as it is big enough to hold its values. However I came across some bizare results! Take for example in the code below: public class test { public static void main(String[] args) { double a=4190.04d; double b=4771.24d; double total =0d; total += a + ...

### 19. Precision for double literals    coderanch.com

Fairly trivial question... class MyClass { public static void main(String[] args) { double d = 2-1.1; // 1 double d2 = 0.9; // 2 System.out.println("d = " + d); //3 System.out.println("d2 = " + d2); //4 } } Running this gives the output: d = 0.8999999999999999 d2 = 0.9 What's bugging me is the second line in the output. It's not ...

### 23. !Java Double Precision    forums.oracle.com

I just started a Intro to Programming class in my high school and I need to know how to set precision on double data types. Please state the answer in understandable format for me as I am new to the terms (We are on JOptionPane and things relating to that). Thank you for your time, I need this answer quickly.

### 24. Quick double precision question    forums.oracle.com

Hi everybody, Does anyone know if there is an easy way to round off and print out a double to two digits after the decimal point? I know you can use Double.toString(), substring(), and Math.ceil, but I was wondering if there was an easier way. I looked at the Javadoc and didn't see one. Just to be clear, what I'm asking ...

### 25. Double Precision Problems...    forums.oracle.com

Can anyone explain the output of the following code to me? I don't understand why there is a precision issue here. The desired result is what you would get if you used a calculator to increment 1.0 by 0.1 over and over again (i.e. 1.1, 1.2, 1.3, 1.4, 1.5...). Code: double a = 1.0; double b = 2.0; double i = ...

### 26. convert a string to double with precision    forums.oracle.com

I am getting a value amount of say \$45.00 from a jsp and set this value as a string for my other work. then i am changing this string to double by using this statement setAmount(Double.parseDouble(cstmt.getString(1))); my precision is lost when i get this amount it just shows 45.0 how can I get the precision of 45.00 I would appreciate if ...

### 28. Want more precision than double    forums.oracle.com

I am trying to get more precision.. currently I am trying to use double and all i get is the following: 9.133057743108883E41 1.1025795069516013E42 1.1527752133430907E42 I am trying to use BigIntegers but not sure how to use them correctly. double base = 0; base = (double)getASCII(strArr[i1].charAt(i2)); base = base * Math.pow(128, exp); but now doing this stuff in a double(base) gave me ...

### 30. how do I get System.out.format to print out doubles with the same precision    forums.oracle.com

I am fine with that. It still displays all the precision. I am simply looking for a way to quickly print out multiple variables on a sysout while debugging. I want it as syntactically sweet as possible. System.out.println can be a pain when outputting multiple variables like the following: "System.out.println("a: " + a + "; b:" + b + "; c: ...