Develop Reference

Kotlin: SumbyDouble returning additional decimals

I am summing double value from arraylist its giving additional decimals as 99999, how to fix this, please guide
ex
class ExDet{var expName:String ="",var expAmount:Double = 0.0}
val arrayList = ArrayList<ExDet>()
arrayList.add(ExDet("Abc 1",45.66))
arrayList.add(ExDet("DEF 1",10.0))
arrayList.add(ExDet("Lee 1",600.89))
arrayList.add(ExDet("Ifr 1",200.9))
var amt = arrayList.sumByDouble{ it.expAmount }
Expected Value of Amount is :
Amt = 857.45
But it returns
Amt = 857.4499999
Sample Code to Test
data class ExDet(var expName:String ="" ,var expAmount:Double=0.0)
fun main(args: Array<String>) {
val arrayList = ArrayList<ExDet>()
arrayList.add(ExDet("Abc 1",45.66))
arrayList.add(ExDet("DEF 1",10.0))
arrayList.add(ExDet("Lee 1",600.89))
arrayList.add(ExDet("Ifr 1",200.9))
var amt = arrayList.sumByDouble{ it.expAmount }
println("Amount is : $amt")
}

The issue you are confronted with is that floating point numbers are build on top of base 2, not base 10.
Think how you can easily represent a third as a fraction (1/3), but when you convert to decimal you get a repeating (recurring) number after the radix point (i.e. 0.33...). Some decimal numbers are recurring when represented in base-2, e.g. x.9. The computer has a finite number of bits, so the (base-2) number is truncated. All the truncation errors can add up.
You need to round to the required precision (e.g. round(x * 100) / 100).
If you are only interested in how it is displayed then you can use the format function with something like "%.2f".
String.format("%.2f", value)

Prevent numbers from changing according to the locale in android

When the user change the locale in device the numbers are also getting changed according to the selected locale. This is causing NumberFormatException while performing mathematical operations and app is getting crashed. The code snippet which is causing the crash is given below.
public static double ToDataUnitMB(double _dataBytes){
double dDataBytes;
dDataBytes = Double.parseDouble(getDecimalFormat().format(_dataBytes / 1048576));
return dDataBytes; }
This code snippet is causing NumberFormatException and the value in _dataBytes is shown as "७२.४१". Can anyone help me to prevent the number from changing when user change the locale.
Update
I am getting the value "७२.४१" after performing the below operation getDecimalFormat().format(_dataBytes / 1048576)
So while parsing to Double it is showing numberFormatException

Since you're starting with raw _dataBytes you have several options how to format number independent of the locale.
First Approach:
You can modify following snippet to your needs. It will give you the same output regardless of the user locale.
String patern = "###.##"; //your pattern as per need
Locale locale = new Locale("en", "US");
DecimalFormat decimalFormat = (DecimalFormat) NumberFormat.getNumberInstance(locale);
decimalFormat.applyPattern(patern);
double formatedDouble = Double.parseDouble(decimalFormat.format(_dataBytes/(1024*1024f)));
Keep in mind that this method also makes grouping and decimal separators to be fixed, so that comma and dot will alway be used as, respectively, grouping separator and decimal separator.
Second Approach:
If you do not strictly require Double you could generate formatted String with something similar to following method:
String generateFormatedFileSize(long _dataBytes) {
String formatedFileSize = "";
long bytes = _dataBytes;
short unit = 1024;
if (bytes < unit)
formatedFileSize = bytes + " B";
else {
int exp = (int) (Math.log(bytes) / Math.log(unit));
formatedFileSize = String.format("%.1f %sB", bytes / Math.pow(unit, exp), "KMGT".charAt(exp - 1));
}
return formatedFileSize;
}
This formatting will be sensitive to grouping separator and decimal separator, but otherwise insensitive to Locale.
For Local that uses "US" numbering format, this will give you following output:
12.5 KB
5.3 B
8.0 MB
And for Local using "European" numbering format:
12,5 KB
5,3 B
8,0 MB
Off course, these two methods are not exclusive and you could use some mix of these approaches at different parts of the App.

Format textField value with comma - Titanium

I have a textField value as 12345678955. I want to format this value as 1,234,567.8955
Want to seperate the value with comma.
I have tired with some codes. But it doesn't work.

Well, you would want to get your 4 decimal places you would need to divide your number by 10000:
var newNumber = parseInt($.yourTextField.value);
newNumber = Math.round(Number(newNumber)) / 10000;
console.log(newNumber); // 1234567.8955
Next you want to add your commmas:
var parts = newNumber.toString().split(".");
var num = parts[0].replace(/\B(?=(\d{3})+(?!\d))/g, ",") + (parts[1] ? "." + parts[1] : "");
console.log(num); // 1,234,567.8955
Thats the functionality, how you tie that to your textField and by which event listener, is yours to work out.
(answer adapted from https://stackoverflow.com/a/25127753/829989 which you could have easily found on your own)

How can I round numbers (2 decimal) parseXml get(field) in Android

TextView.setText(XMLdata.get("XMLField") + " mm");
input values that are expressed in an abbreviated way:
10,5858555966668 (with comma)
Which I would like to convert into:
10,58

if your XMLdata.get("XMLField") value is float u can do the following code
String finalValue = String.format(
"%.2f", XMLdata.get("XMLField"));
TextView.setText(finalValue + " mm");
if your XMLdata.get("XMLField") is String convert it into float do the above method.

TextView.setText((Math.floor(MathXMLdata.get("XMLField") * 100.0) / 100.0).toString() + " mm");
This converts 10,5858555966668 to 1058,58555966668, rounds it to 1058 and converts it back to 10,58.
Note: Math.floor always rounds down (cuts off all missing fractional numbers). If you intend to round to the closest value, use Math.round.

Thank you, thank you very much rmkrishna and Faro ((= I do it with
TextView.setText(String.format("%.2f",Double.parseDouble(XMLData.get("Son7GunlukSagis").replace(",", ".")))+ " mm");

Add a number and a Text Input value with adobe flex

I am trying to add a number and a text input value to display in a label. here is my code thus far.
'lblAnswer.text = bloodglucose + 100;'
Please tell me what I am doing wrong.

Please try following answer -
bloodglucose += 100;
lblAnswer.text = String(bloodglucose);
Hope this will work :)

Sunil is correct - when doing mixed type addition, the UI input first needs to be coerced to either int or Number. IE: Number(bloodglucose) + 100; This assumes bloodglucose is actually a getter to the input text reference. If it's not, then you need to coerce the property and not the id of the component.
Getter: public function get bloodglucose():Number { return Number(myInput.text); }
In method: lblAnswer.text = bloodglucose + 100;
or (bloodglucose is a UIComponent):
In method: lblAnswer.text = Number(bloodglucose.text) + 100;

You should use String(int i)
lblAnswer.text = String(bloodglucose + 100);
Update: What about something like this:
var i:int = bloodglucose + 100;
var s:String = String(i);
lblAnswer.text = s;

** Update ,
I am changing the code from the update that was previously posted. I initially found that because I was including the string value inside of the equation this is what was prompting an error. You have to wrap the converted components to Number inside of the string all together. Basically convert the components to a number, then convert the answer received into a string.
Below is an example of the wrong code.
txtAnswer = (String(Number(bloodglucose)+100)) / 36)).toFixed(2)
Below this line is the fixed code.
txtAnswer.text = String( (Number(bloodglucose.text) + (Number(100))/ (Number(36))).toFixed(2) ;
The .toFixed Property signifies how many decimal places I want the returned value to display.