Despite the rather clear documentation which says that parseFloat() can return NaN as a value, when I write a block like: if ( NaN == parseFloat(input.text) ) { errorMessage.text = "Please enter a number." } I am warned that the comparison will always be false. And testing shows the warning to be correct. Where is the corrected doc...
What's the best way to use NaNs in C++? I found std::numeric_limits<double>::quiet_NaN() and std::numeric_limits<double>::signaling_NaN(). I'd like to use signaling_NaN to represent an uninitialized variable as follows: double diameter = std::numeric_limits<double>::signaling_NaN(); This, however, signals (raises an exception) on as...
After looking at another question on SO (Using NaN in C++) I became curious about std::numeric_limits<double>::signaling_NaN(). I could not get signaling_NaN to throw an exception. I thought perhaps by signaling it really meant a signal so I tried catching SIGFPE but nope... Here is my code: double my_nan = numeric_limits<double>::sig...
I have compiled code that erroneously tries to add a number and Double.NaN. I'm wondering if it's throwing an exception that's not getting caught? Does anyone know how that situation is handled? Thanks. ...
I am working on an old database I inherited from my predecessors. In it, some float fields contains NaN where there should be a null. The following SQL doesn't work because it doesn't recognize NaN. UPDATE xxx SET column= null WHERE column=NaN How can I do this? ...
I have the following code... if (Price_Foreign != Double.NaN) { output.Append(spacer); output.Append(String.Format("{0,-10:C} USD",Price_Foreign)); } Which outputs: NaN USD What gives? I'm using Double.NaN to indicate that the value doesn't exist, and shouldn't be output. ...
if i want to test the result of an expression and the function would return NaN how would i check that? examples: $('amount').value.toInt()!='NaN' ^ does not work and i assume that the returned value is not a string, $('amount').value.toInt()!=NaN^ doesnt seem to work either and this one seems obvious so how do i check wether the returne...
is there an isnan() function? p.s. I'm in mingw (if that makes a difference) UPDATE Thanks for the responses I had this solved by using isnan() form <math.h>, which doesn't exist in <cmath>, which I was #includeing at first. ...
I'm working on a java application,use double type to save value of unitprice,qty etc.I found some of these values show in MSSQL are NAN and throws infinite error when I try to reuse it.This is so unreasonable,I can save it but can not use it anymore!I think the NAN value in MSSQL must be valid when it first presence in java,so i can save...
I have a set of balloons that I am trying to get to bounce off of each other like balls. When I start to move them and then detect collision, the routine for the collisions eventually returns a NAN for the velocity of the balloons. I end up with a position of something like x=270, y= -nan(0x400000). I've been looking at the code all d...
I'm using C# with the XNA library and I'm getting NaNs cropping up in my Vector3 objects. Is there a way to break into the debugger when the offending calculation happens (e.g. a divide by zero)? Currently the program just continues running. I'm using VS2008 Professional. All the exceptions in the Exceptions dialog are selected in the...
I am pulling a value via JavaScript from a textbox. If the textbox is empty, it returns NaN. I want to return an empty string if it's null, empty,etc. What check do I do? if(NAN = tb.value) ? ...
Also "NaN".to_f returns 0 instead of NaN. ...
Hi, all. I have a quick question (I hope!). In JS, why does isNaN(" ") evaluate to false, but isNaN(" x") evaluate to true? I'm performing numerical operations on a text input field, and am checking if the field is null, "", or NaN. When someone types a handful of spaces into the field, my validation fails on all three, and I'm co...
I am writing algorithms that work on series of numeric data, where sometimes, a value in the series needs to be null. However, because this application is performance critical, I have avoided the use of nullable types. I have perf tested the algorithms to specifically compare the performance of using nullable types vs non-nullable type...
VB6 doesn't appear to make it that easy to store +infinity, -infinity and NaN into double vars. It would help if it could so that I could do comparisons with those values in the context of complex numbers. How? ...
How can we use them in our codes, and what will cause NaN(not a number)? ...
Is it a good idea to use IEEE754 floating point NaN (not-a-number) for values which are undefined for non-mathematical reasons? In our case they are not yet set because the values have not been received from some other device. The context is an embedded system using IEC1131 REAL32 values. Edit: The programming language is C, so we would...
How do I create or test for NaN or infinite values in Perl? ...
How do I initialize number with NaN in Borland C++? duplicate: Using NaN in C++? ...