Best Way to Parsedouble With Comma as Decimal Separator

Best way to parseDouble with comma as decimal separator?

Use java.text.NumberFormat:

NumberFormat format = NumberFormat.getInstance(Locale.FRANCE);
Number number = format.parse("1,234");
double d = number.doubleValue();

Updated:

To support multi-language apps use:

NumberFormat format = NumberFormat.getInstance(Locale.getDefault());

How to parse String, with both decimal separators comma and dot as well, to Double

Like Mohit Thakur said, but compilable.

NumberFormat format = NumberFormat.getInstance(Locale.FRANCE);
try {
    Number number = format.parse(formDto.getWeight().replace('.', ','));
    kitten.setWeight(number.doubleValue());
} catch (ParseException e) {
    e.printStackTrace();
}

Parse strings to double with comma and point

You want to treat dot (.) like comma (,). So, replace

if (double.TryParse(values[i, j], out tmp))

with

if (double.TryParse(values[i, j].Replace('.', ','), out tmp))

Is there a standard way to parse a float using a custom decimal separator

Alternative 1: Replace "," with "." (as already suggested)

Alternative 2: Use DecimalFormat

    float value;
    DecimalFormat df = new DecimalFormat();
    DecimalFormatSymbols symbols = new DecimalFormatSymbols();
    symbols.setDecimalSeparator(',');
    df.setDecimalFormatSymbols(symbols);
    try {
        Number n = df.parse("1,234");
        value = n.floatValue();            
    } catch (ParseException e) {
        e.printStackTrace();
    }

Alternative 3: Use locale

Convert a String to Double - Java

Have a look at java.text.NumberFormat. For example:

import java.text.*;
import java.util.*;

public class Test
{
    // Just for the sake of a simple test program!
    public static void main(String[] args) throws Exception
    {
        NumberFormat format = NumberFormat.getInstance(Locale.US);

        Number number = format.parse("835,111.2");
        System.out.println(number); // or use number.doubleValue()
    }
}

Depending on what kind of quantity you're using though, you might want to parse to a BigDecimal instead. The easiest way of doing that is probably:

BigDecimal value = new BigDecimal(str.replace(",", ""));

or use a DecimalFormat with setParseBigDecimal(true):

DecimalFormat format = (DecimalFormat) NumberFormat.getInstance(Locale.US);
format.setParseBigDecimal(true);
BigDecimal number = (BigDecimal) format.parse("835,111.2");

DecimalFormat(0.0) returns data with a comma as separator instead of a point

You can (and you actually need to avoid localization) actively configure the DecimalFormat with more detail as follows:

public class Main {
    public static void main(String[] args) throws Exception {
        DecimalFormat df = new DecimalFormat("0.0");
        DecimalFormatSymbols decimalFormatSymbols = new DecimalFormatSymbols();
        decimalFormatSymbols.setDecimalSeparator('.');
        df.setDecimalFormatSymbols(decimalFormatSymbols);
        
        System.out.println(df.format(10.4));  // prints 10,4 instead of 10.4
        System.out.println(df.format(100.5)); // prints 100,5 instead of 100.5
        System.out.println(df.format(3000.3));// prints 3000,3 instead of 3000.3
    }
}

You can read more details in the reference documentation, where an important snippet can be read:

Special Pattern Characters

(...)

The characters listed here are used
in non-localized patterns. Localized patterns use the corresponding
characters taken from this formatter's DecimalFormatSymbols object
instead, and these characters lose their special status.

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