Converting double to string
JavaAndroidJava Problem Overview
I am not sure it is me or what but I am having a problem converting a double to string.
here is my code:
double total = 44;
String total2 = Double.toString(total);
Am i doing something wrong or am i missing a step here.
I get error NumberFormatException
when trying to convert this.
totalCost.setOnTouchListener(new OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
try {
double priceG = Double.parseDouble(priceGal.getText().toString());
double valG = Double.parseDouble(volGal.toString());
double total = priceG * valG;
String tot = new Double(total).toString();
totalCost.setText(tot);
} catch(Exception e) {
Log.e("text", e.toString());
}
return false;
}
});
I am trying to do this in an onTouchListener. Ill post more code, basically when the user touches the edittext box i want the information to calculate a fill the edittext box.
Java Solutions
Solution 1 - Java
double total = 44;
String total2 = String.valueOf(total);
This will convert double to String
Solution 2 - Java
Using Double.toString(), if the number is too small or too large, you will get a scientific notation like this: 3.4875546345347673E-6. There are several ways to have more control of output string format.
double num = 0.000074635638;
// use Double.toString()
System.out.println(Double.toString(num));
// result: 7.4635638E-5
// use String.format
System.out.println(String.format ("%f", num));
// result: 0.000075
System.out.println(String.format ("%.9f", num));
// result: 0.000074636
// use DecimalFormat
DecimalFormat decimalFormat = new DecimalFormat("#,##0.000000");
String numberAsString = decimalFormat.format(num);
System.out.println(numberAsString);
// result: 0.000075
Use String.format() will be the best convenient way.
Solution 3 - Java
This code compiles and works for me. It converts a double to a string using the calls you tried.
public class TestDouble {
public static void main(String[] args) {
double total = 44;
String total2 = Double.toString(total);
System.out.println("Double is " + total2);
}
}
I am puzzled by your seeing the NumberFormatException. Look at the stack trace. I'm guessing you have other code that you are not showing in your example that is causing that exception to be thrown.
Solution 4 - Java
The exception probably comes from the parseDouble() calls. Check that the values given to that function really reflect a double.
Solution 5 - Java
double total = 44;
String total2 = new Double(total).toString();
Solution 6 - Java
double priceG = Double.parseDouble(priceGal.getText().toString());
double valG = Double.parseDouble(volGal.toString());
double priceG = Double.parseDouble(priceGal.getText().toString());
double valG = Double.parseDouble(volGal.toString());
double priceG = Double.parseDouble(priceGal.getText().toString());
double valG = Double.parseDouble(volGal.toString());
it works. got to be repetitive.
Solution 7 - Java
Kotlin
You can use .toString
directly on any data type in kotlin, like
val d : Double = 100.00
val string : String = d.toString()
Solution 8 - Java
This is a very old post, but this may be the easiest way to convert it:
double total = 44;
String total2 = "" + total;
Solution 9 - Java
double priceG = Double.parseDouble(priceGal.getText().toString());
double valG = Double.parseDouble(volGal.toString());
One of those is throwing the exception. You need to add some logging/printing to see what's in volGal
and priceGal
- it's not what you think.
Solution 10 - Java
double.toString()
should work. Not the variable type Double
, but the variable itself double
.
Solution 11 - Java
Complete Info
You can use String.valueOf() for float, double, int, boolean etc.
double d = 0;
float f = 0;
int i = 0;
short i1 = 0;
char c = 0;
boolean bool = false;
char[] chars = {};
Object obj = new Object();
String.valueOf(d);
String.valueOf(i);
String.valueOf(i1);
String.valueOf(f);
String.valueOf(c);
String.valueOf(chars);
String.valueOf(bool);
String.valueOf(obj);
Solution 12 - Java
There are three ways to convert double to String.
-
Double.toString(d)
-
String.valueOf(d)
-
""+d
public class DoubleToString {
public static void main(String[] args) { double d = 122; System.out.println(Double.toString(d)); System.out.println(String.valueOf(d)); System.out.println(""+d); }
}
String to double
- Double.parseDouble(str);
Solution 13 - Java
Just use the following:
doublevalue+"";
This will work for any data type.
Example:
Double dd=10.09;
String ss=dd+"";
Solution 14 - Java
Use StringBuilder
class, like so:
StringBuilder meme = new StringBuilder(" ");
// Convert and append your double variable
meme.append(String.valueOf(doubleVariable));
// Convert string builder to string
jTextField9.setText(meme.toString());
You will get you desired output.
Solution 15 - Java
How about when you do the
totalCost.setText(tot);
You just do
totalCost.setText( "" + total );
Where the "" + < variable > will convert it to string automaticly
Solution 16 - Java
When you would like to format the decimal and convert it to a String
DecimalFormat
helps much.
Example:
DecimalFormat format = new DecimalFormat("#.####");
format.format(yourDoubleObject);
These are various symbols that are supported as part of pattern in DecimalFomat.
Solution 17 - Java
This is a very old post, but java double to string conversion can be done in many ways, I will go through them one by one with example code snippets.
1. Using + operator
This is the easiest way to convert double to string in java.
double total = 44;
String total2 = total + "";
2. Double.toString()
We can use Double class toString
method to get the string representation of double in decimal points. Below code snippet shows you how to use it to convert double to string in java.
double total = 44;
String total2 = Double.toString(total);
3. String.valueOf()
double total = 44;
String total2 = String.valueOf(total);
4. new Double(double l)
Double constructor with double argument has been deprecated in Java 9, but you should know it.
double total = 44;
//deprecated from Java 9, use valueOf for better performance
String total2 = new Double(total).toString();
5. String.format()
We can use Java String format method to convert double to String in our programs.
double total = 44;
String total2 = String.format("%f", total);
6. DecimalFormat
We can use DecimalFormat
class to convert double to String. We can also get string representation with specified decimal places and rounding of half-up.
double total = 44;
String total2 = DecimalFormat.getNumberInstance().format(total);
//if you don't want formatting
total2 = new DecimalFormat("#.0#").format(total); // rounded to 2 decimal places
total2 = new DecimalFormat("#.0#").format(44); // rounded to 2 decimal places
7. StringBuilder, StringBuffer
We can use StringBuilder and StringBuffer append function to convert double to string.
double total = 44;
String total2 = new StringBuilder().append(total).toString();