This question already has answers here:
Why does integer division in C# return an integer and not a float?
(8 answers)
Closed 6 years ago.
I am really confused why this is happening, my code:
double x = Math.Sqrt(2/3);
MessageBox.Show(x.ToString());
Displays 0.
The answer is
0.8164, I know I will also have to use Math.Round to round this up, but for the moment the issue is I'm getting 0
The problem is caused by automatic integer evaluation of the numbers. Use:
double x = Math.Sqrt(2f/3f);
MessageBox.Show(x.ToString());
2 / 3 is an integer operation, what you want is 2.0 / 3 which means I want to use floating point numbers.
What you consider an Intereger is different from what you know from Maths. In programming languages it means that a result of an int-operation is allways an integer in itself.
In your example 2 / 3 is an integer-operation which means the result is rounded down to the nearest integer, which is zero. To avoid this indicate that at least one of your operands should be treates as some floating-point value, either using 2.0 or 2f (alternativly 3.0 or 3f).
Related
This question already has answers here:
Why does integer division in C# return an integer and not a float?
(8 answers)
Closed 3 years ago.
I am grabbing total RAM of a computer system and available RAM and trying to work out what percentage is available.
I am using the following code:
double percent = my.Info.AvailablePhysicalMemory / my.Info.TotalPhysicalMemory;
and have also tried:
decimal percent = my.Info.AvailablePhysicalMemory / my.Info.TotalPhysicalMemory;
I am sure it's an issue with the type but I am unsure why both methods give a result of 0.
The actual values are Total: 17072574464 and Available: 8746000384. The values come back from the system cast as ulong. So what does percent always equal 0? If I put the numbers in directly it works fine. Just can't use the ulong variables - hence why I am sure it's my lack of experience with types in C# that is the problem.
You are trying to divide an integer by an integer, which always rounds down. You need to convert to a floating point number before you divide; for example:
double percent = my.Info.AvailablePhysicalMemory * 1.0 / my.Info.TotalPhysicalMemory;
This question already has answers here:
Why is floating point arithmetic in C# imprecise?
(3 answers)
Closed 8 years ago.
I am trying to find out modulo in c# as i know remainder is obtained on doing a modulo b= remainder so here a%b=remainder the same i tried to do like this:
var distanceFactor = slider.Value % distance;
But the value on debugging of slider.Value= 2.0 and distance =0.1 and distanceFactor i found surprisingly is 0.0999999999.. and i was expecting it to be 0.
Is it due to var ? what could be the reason for this non zero value.?
And how to do the solution of this problem ? because on rounding of this 0.0999999999 becomes 0.1 ans my control never go in condition if(distanceFactor==0) (and roundoff is also necessary in current situation).Is there any alternative to achieve it ?
This is expected behavior. A floating point number does not exactly represent a decimal number like the type decimal would do. Look at What Every Computer Scientist Should Know About Floating-Point Arithmetic for a detailed description.
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
Divide problem
Why does c# show the output of this code as 0??
MessageBox.Show((5/6).ToString);
Because unless you specify that you want the operation to result in a Double the operation results in an Integer, and so the fractional result is dropped and you are left with just the whole number of 0.
5/6 is basically integral division, which turns out to be 0. The type of both operands is int.
I think what you want is : 5.0/6.0.
In fact, 5.0/6.0, 5/6.0, 5.0/6, all would give same result. That is, as long as, one operand is double, it would be a double division, and the type of the result would be double as well.
It is dividing an integer by and integer and will return an integer, I believe it always returns the floor value. Try Messagebox.Show((5.0/6.0).ToString());
Because you are doing integer division. If you want non-integer division you should do something like 5 / 6d
The compiler assumes that the numbers are Int, which must be whole numbers. Thus, it is rounding the answer. To return the decimal answer, use this:
MessageBox.Show((5d/6d).ToString());
This question already has answers here:
Closed 12 years ago.
Possible Duplicates:
Ints and Doubles doing division
1/252 = 0 in c#?
Hi,
Maybe because it's Friday, but I cannot understand this:
(Double)1/2 = 0.5
(Double)1/(Double)2 = 0.5
(Double)((Double)1/(Double)2) = 0.5
(Double)(1/2) = 0.0
Why the last operation is 0? :S
Kind regards.
Because 1 and 2 are integers. The result is 0. If you cast that to a double, it's still 0. This question was asked just a couple of days ago.
If you divide two ints, then the result will also be int. So 1/2 gives you a zero which is an integer. Then you are casting 0 to double, which is still zero.
Everyone's given you the correct answer so far, I'm adding this so other readers don't miss it in the comments.
Use the same rule as regular math. Inner Parenthesis first. So in the first example, the 1 is casted to a double before the division occurs, making the result a double (division of int and double results in double). This rings true if it is (Double)1/2 or 1/(Double)2. So in the last example, (Double)(1/2), the (1/2) is performed first, int on int, resulting in int. Then the (Double) casts it to a Double. Hope this not only helps you but anyone else curious about this question. I myself have had many times where I had a long equation and literally had to cast each parameter of the equation to a double.
Try (double)(1.0/2.0) - that will give the answer you expect.
As already written, the problem is the type. You can use suffixes to make sure the type is correct:
1d/2d=0.5
(Double)1/2 = 0.5
(Double)1/(Double)2 = 0.5
(Double)((Double)1/(Double)2) = 0.5
(Double)(1/2) = 0.0
In first three cases You cast the integer value (thas is default type for number when you do not use suffix or does not contain dot ) to Double and then do the division with an integer value in first case and with double for 2 and 3, in contrast to last (4) case where the brackets change the order of operation first You divide two integers, and after that cast the result to Double.
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
c# - How do I round a decimal value to 2 decimal places (for output on a page)
i have value of 1.564 and 1.565 i need round this value to 1.56 and 1.56,which function suitable for this in c#.
do a multiply by 100 followed by a floor and followed by a divide by hundred. I am sure that there is a better way of doing it though
Math.floor(n*100)/100
To remove the less significant digits (1.348 -> 1.34):
Math.Floor(number * 100) / 100;
To round the number to two decimals:
Math.Round(number, 2);
To represent it as a string, for display:
number.ToString("#.00");