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Questions tagged [double]

Double is a primitive data type used to store fractional numbers that holds a double-precision floating-point (often 64 bits).

In C and C++ double must be at least as large as float (another floating-point type), but its actual size can vary from system to system as it is implementation-defined. It is typically twice the size of float. Many systems store doubles in binary64, a format described in the IEEE 754 technical standard.

Java has a very strict definition for double, requiring it to be stored in binary64 (which is also called double-precision).

More information:

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Difference between decimal, float and double in .NET?

What is the difference between decimal, float and double in .NET? When would someone use one of these?
Tom
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7 answers

decimal vs double! - Which one should I use and when?

I keep seeing people using doubles in C#. I know I read somewhere that doubles sometimes lose precision. My question is when should a use a double and when should I use a decimal type? Which type is suitable for money computations? (ie. greater…
Soni Ali
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How to convert a Decimal to a Double in C#?

I want to use a Track-Bar to change a Form's opacity. This is my code: decimal trans = trackBar1.Value / 5000; this.Opacity = trans; When I build the application, it gives the following error: Cannot implicitly convert type decimal to double I…
Eggs McLaren
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Why does Math.round(0.49999999999999994) return 1?

In the following program you can see that each value slightly less than .5 is rounded down, except for 0.5. for (int i = 10; i >= 0; i--) { long l = Double.doubleToLongBits(i + 0.5); double x; do { x =…
Peter Lawrey
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How to nicely format floating numbers to string without unnecessary decimal 0's

A 64-bit double can represent integer +/- 253 exactly. Given this fact, I choose to use a double type as a single type for all my types, since my largest integer is an unsigned 32-bit number. But now I have to print these pseudo integers, but the…
Pyrolistical
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Round a double to 2 decimal places

If the value is 200.3456, it should be formatted to 200.34. If it is 200, then it should be 200.00.
Rajesh
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Correct format specifier for double in printf

What is the correct format specifier for double in printf? Is it %f or is it %lf? I believe it's %f, but I am not sure. Code sample #include int main() { double d = 1.4; printf("%lf", d); // Is this wrong? }
Leopard
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Rounding a double value to x number of decimal places in swift

Can anyone tell me how to round a double value to x number of decimal places in Swift? I have: var totalWorkTimeInHours = (totalWorkTime/60/60) With totalWorkTime being an NSTimeInterval (double) in second. totalWorkTimeInHours will give me the…
Leighton
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Checking if a double (or float) is NaN in C++

Is there an isnan() function? PS.: I'm in MinGW (if that makes a difference). I had this solved by using isnan() from , which doesn't exist in , which I was #includeing at first.
hasen
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Double vs. BigDecimal?

I have to calculate some floating point variables and my colleague suggest me to use BigDecimal instead of double since it will be more precise. But I want to know what it is and how to make most out of BigDecimal?
Truong Ha
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How can I divide two integers to get a double?

How do I divide two integers to get a double?
leora
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Convert String to double in Java

How can I convert a String such as "12.34" to a double in Java?
TinyBelly
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How do you test to see if a double is equal to NaN?

I have a double in Java and I want to check if it is NaN. What is the best way to do this?
Eric Wilson
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Round double in two decimal places in C#?

I want to round up double value in two decimal places in c# how can i do that? double inputValue = 48.485; after round up inputValue = 48.49; Related: c# - How do I round a decimal value to 2 decimal places (for output on a page)
sanjeev40084
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When should I use double instead of decimal?

I can name three advantages to using double (or float) instead of decimal: Uses less memory. Faster because floating point math operations are natively supported by processors. Can represent a larger range of numbers. But these advantages seem to…
Jamie Ide
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