Related
Can I do it with System.out.print?
You can use the printf method, like so:
System.out.printf("%.2f", val);
In short, the %.2f syntax tells Java to return your variable (val) with 2 decimal places (.2) in decimal representation of a floating-point number (f) from the start of the format specifier (%).
There are other conversion characters you can use besides f:
d: decimal integer
o: octal integer
e: floating-point in scientific notation
You can use DecimalFormat. One way to use it:
DecimalFormat df = new DecimalFormat();
df.setMaximumFractionDigits(2);
System.out.println(df.format(decimalNumber));
Another one is to construct it using the #.## format.
I find all formatting options less readable than calling the formatting methods, but that's a matter of preference.
I would suggest using String.format() if you need the value as a String in your code.
For example, you can use String.format() in the following way:
float myFloat = 2.001f;
String formattedString = String.format("%.02f", myFloat);
double d = 1.234567;
DecimalFormat df = new DecimalFormat("#.##");
System.out.print(df.format(d));
float f = 102.236569f;
DecimalFormat decimalFormat = new DecimalFormat("#.##");
float twoDigitsF = Float.valueOf(decimalFormat.format(f)); // output is 102.24
You may use this quick codes below that changed itself at the end. Add how many zeros as refers to after the point
float y1 = 0.123456789;
DecimalFormat df = new DecimalFormat("#.00");
y1 = Float.valueOf(df.format(y1));
The variable y1 was equals to 0.123456789 before. After the code it turns into 0.12 only.
float floatValue=22.34555f;
System.out.print(String.format("%.2f", floatValue));
Output is 22.35.
If you need 3 decimal points change it to "%.3f".
Many people have mentioned DecimalFormat. But you can also use printf if you have a recent version of Java:
System.out.printf("%1.2f", 3.14159D);
See the docs on the Formatter for more information about the printf format string.
A simple trick is to generate a shorter version of your variable by multiplying it with e.g. 100, rounding it and dividing it by 100.0 again. This way you generate a variable, with 2 decimal places:
double new_variable = Math.round(old_variable*100) / 100.0;
This "cheap trick" was always good enough for me, and works in any language (I am not a Java person, just learning it).
Look at DecimalFormat
Here is an example from the tutorial:
DecimalFormat myFormatter = new DecimalFormat(pattern);
String output = myFormatter.format(value);
System.out.println(value + " " + pattern + " " + output);
If you choose a pattern like "###.##", you will get two decimal places, and I think that the values are rounded up. You will want to look at the link to get the exact format you want (e.g., whether you want trailing zeros)
To print a float up to 2 decimal places in Java:
float f = (float)11/3;
System.out.print(String.format("%.2f",f));
OUTPUT: 3.67
> use %.3f for up to three decimal places.
Below is code how you can display an output of float data with 2 decimal places in Java:
float ratingValue = 52.98929821f;
DecimalFormat decimalFormat = new DecimalFormat("#.##");
float twoDigitsFR = Float.valueOf(decimalFormat.format(ratingValue)); // output is 52.98
OK - str to float.
package test;
import java.text.DecimalFormat;
public class TestPtz {
public static void main(String[] args) {
String preset0 = "0.09,0.20,0.09,0.07";
String[] thisto = preset0.split(",");
float a = (Float.valueOf(thisto[0])).floatValue();
System.out.println("[Original]: " + a);
a = (float) (a + 0.01);
// Part 1 - for display / debug
System.out.printf("[Local]: %.2f \n", a);
// Part 2 - when value requires to be send as it is
DecimalFormat df = new DecimalFormat();
df.setMinimumFractionDigits(2);
df.setMaximumFractionDigits(2);
System.out.println("[Remote]: " + df.format(a));
}
}
Output:
run:
[Original]: 0.09
[Local]: 0.10
[Remote]: 0.10
BUILD SUCCESSFUL (total time: 0 seconds)
One issue that had me for an hour or more, on DecimalFormat- It handles double and float inputs differently. Even change of RoundingMode did not help. I am no expert but thought it may help someone like me. Ended up using Math.round instead.
See below:
DecimalFormat df = new DecimalFormat("#.##");
double d = 0.7750;
System.out.println(" Double 0.7750 -> " +Double.valueOf(df.format(d)));
float f = 0.7750f;
System.out.println(" Float 0.7750f -> "+Float.valueOf(df.format(f)));
// change the RoundingMode
df.setRoundingMode(RoundingMode.HALF_UP);
System.out.println(" Rounding Up Double 0.7750 -> " +Double.valueOf(df.format(d)));
System.out.println(" Rounding Up Float 0.7750f -> " +Float.valueOf(df.format(f)));
Output:
Double 0.7750 -> 0.78
Float 0.7750f -> 0.77
Rounding Up Double 0.7750 -> 0.78
Rounding Up Float 0.7750f -> 0.77
public String getDecimalNumber(String number) {
Double d=Double.parseDouble(number);
return String.format("%.5f", d);
}
Take care of NumberFormatException as well
small simple program for demonstration:
import java.io.*;
import java.util.Scanner;
public class twovalues {
public static void main(String args[]) {
float a,b;
Scanner sc=new Scanner(System.in);
System.out.println("Enter Values For Calculation");
a=sc.nextFloat();
b=sc.nextFloat();
float c=a/b;
System.out.printf("%.2f",c);
}
}
Just do String str = System.out.printf("%.2f", val).replace(",", "."); if you want to ensure that independently of the Locale of the user, you will always get / display a "." as decimal separator. This is a must if you don't want to make your program crash if you later do some kind of conversion like float f = Float.parseFloat(str);
Try this:-
private static String getDecimalFormat(double value) {
String getValue = String.valueOf(value).split("[.]")[1];
if (getValue.length() == 1) {
return String.valueOf(value).split("[.]")[0] +
"."+ getValue.substring(0, 1) +
String.format("%0"+1+"d", 0);
} else {
return String.valueOf(value).split("[.]")[0]
+"." + getValue.substring(0, 2);
}
}
Can I do it with System.out.print?
You can use the printf method, like so:
System.out.printf("%.2f", val);
In short, the %.2f syntax tells Java to return your variable (val) with 2 decimal places (.2) in decimal representation of a floating-point number (f) from the start of the format specifier (%).
There are other conversion characters you can use besides f:
d: decimal integer
o: octal integer
e: floating-point in scientific notation
You can use DecimalFormat. One way to use it:
DecimalFormat df = new DecimalFormat();
df.setMaximumFractionDigits(2);
System.out.println(df.format(decimalNumber));
Another one is to construct it using the #.## format.
I find all formatting options less readable than calling the formatting methods, but that's a matter of preference.
I would suggest using String.format() if you need the value as a String in your code.
For example, you can use String.format() in the following way:
float myFloat = 2.001f;
String formattedString = String.format("%.02f", myFloat);
double d = 1.234567;
DecimalFormat df = new DecimalFormat("#.##");
System.out.print(df.format(d));
float f = 102.236569f;
DecimalFormat decimalFormat = new DecimalFormat("#.##");
float twoDigitsF = Float.valueOf(decimalFormat.format(f)); // output is 102.24
You may use this quick codes below that changed itself at the end. Add how many zeros as refers to after the point
float y1 = 0.123456789;
DecimalFormat df = new DecimalFormat("#.00");
y1 = Float.valueOf(df.format(y1));
The variable y1 was equals to 0.123456789 before. After the code it turns into 0.12 only.
float floatValue=22.34555f;
System.out.print(String.format("%.2f", floatValue));
Output is 22.35.
If you need 3 decimal points change it to "%.3f".
Many people have mentioned DecimalFormat. But you can also use printf if you have a recent version of Java:
System.out.printf("%1.2f", 3.14159D);
See the docs on the Formatter for more information about the printf format string.
A simple trick is to generate a shorter version of your variable by multiplying it with e.g. 100, rounding it and dividing it by 100.0 again. This way you generate a variable, with 2 decimal places:
double new_variable = Math.round(old_variable*100) / 100.0;
This "cheap trick" was always good enough for me, and works in any language (I am not a Java person, just learning it).
Look at DecimalFormat
Here is an example from the tutorial:
DecimalFormat myFormatter = new DecimalFormat(pattern);
String output = myFormatter.format(value);
System.out.println(value + " " + pattern + " " + output);
If you choose a pattern like "###.##", you will get two decimal places, and I think that the values are rounded up. You will want to look at the link to get the exact format you want (e.g., whether you want trailing zeros)
To print a float up to 2 decimal places in Java:
float f = (float)11/3;
System.out.print(String.format("%.2f",f));
OUTPUT: 3.67
> use %.3f for up to three decimal places.
Below is code how you can display an output of float data with 2 decimal places in Java:
float ratingValue = 52.98929821f;
DecimalFormat decimalFormat = new DecimalFormat("#.##");
float twoDigitsFR = Float.valueOf(decimalFormat.format(ratingValue)); // output is 52.98
OK - str to float.
package test;
import java.text.DecimalFormat;
public class TestPtz {
public static void main(String[] args) {
String preset0 = "0.09,0.20,0.09,0.07";
String[] thisto = preset0.split(",");
float a = (Float.valueOf(thisto[0])).floatValue();
System.out.println("[Original]: " + a);
a = (float) (a + 0.01);
// Part 1 - for display / debug
System.out.printf("[Local]: %.2f \n", a);
// Part 2 - when value requires to be send as it is
DecimalFormat df = new DecimalFormat();
df.setMinimumFractionDigits(2);
df.setMaximumFractionDigits(2);
System.out.println("[Remote]: " + df.format(a));
}
}
Output:
run:
[Original]: 0.09
[Local]: 0.10
[Remote]: 0.10
BUILD SUCCESSFUL (total time: 0 seconds)
One issue that had me for an hour or more, on DecimalFormat- It handles double and float inputs differently. Even change of RoundingMode did not help. I am no expert but thought it may help someone like me. Ended up using Math.round instead.
See below:
DecimalFormat df = new DecimalFormat("#.##");
double d = 0.7750;
System.out.println(" Double 0.7750 -> " +Double.valueOf(df.format(d)));
float f = 0.7750f;
System.out.println(" Float 0.7750f -> "+Float.valueOf(df.format(f)));
// change the RoundingMode
df.setRoundingMode(RoundingMode.HALF_UP);
System.out.println(" Rounding Up Double 0.7750 -> " +Double.valueOf(df.format(d)));
System.out.println(" Rounding Up Float 0.7750f -> " +Float.valueOf(df.format(f)));
Output:
Double 0.7750 -> 0.78
Float 0.7750f -> 0.77
Rounding Up Double 0.7750 -> 0.78
Rounding Up Float 0.7750f -> 0.77
public String getDecimalNumber(String number) {
Double d=Double.parseDouble(number);
return String.format("%.5f", d);
}
Take care of NumberFormatException as well
small simple program for demonstration:
import java.io.*;
import java.util.Scanner;
public class twovalues {
public static void main(String args[]) {
float a,b;
Scanner sc=new Scanner(System.in);
System.out.println("Enter Values For Calculation");
a=sc.nextFloat();
b=sc.nextFloat();
float c=a/b;
System.out.printf("%.2f",c);
}
}
Just do String str = System.out.printf("%.2f", val).replace(",", "."); if you want to ensure that independently of the Locale of the user, you will always get / display a "." as decimal separator. This is a must if you don't want to make your program crash if you later do some kind of conversion like float f = Float.parseFloat(str);
Try this:-
private static String getDecimalFormat(double value) {
String getValue = String.valueOf(value).split("[.]")[1];
if (getValue.length() == 1) {
return String.valueOf(value).split("[.]")[0] +
"."+ getValue.substring(0, 1) +
String.format("%0"+1+"d", 0);
} else {
return String.valueOf(value).split("[.]")[0]
+"." + getValue.substring(0, 2);
}
}
I have tried the following code but it is not working in a particular case.
Eg: Suppose, I have a double value=2.5045 and i want it to be rounded off upto two decimal places using the below code.After rounding off, i get the answer as 2.5. But I want the answer to be 2.50 instead. In this case,zero is trimmed off. Is there any way to retain the zero so as to get the desired answer as 2.50 after rounding off.
private static DecimalFormat twoDForm = new DecimalFormat("#.##");
public static double roundTwoDecimals(double amount) {
return Double.valueOf(twoDForm.format(amount));
}
try this pattern
new DecimalFormat("0.00");
but this will change only formatting, double cannot hold number of digits after decimal poin, try BigDecimal
BigDecimal bd = new BigDecimal(2.5045).setScale(2, RoundingMode.HALF_UP);
Look at the documentation for DecimalFormat. For # it says:
Digit, zero shows as absent
0 is probably what you want:
Digit
So what you are looking for is either "0.00" or "#.00" as a format string, depending on whether you want the first digit before the period, to be visible in case the numbers absolute value is smalle than 0.
Try this
DecimalFormat format = new DecimalFormat("#");
format.setMinimumFractionDigits(2);
answer.setText(format.format(data2));
Try This
double d = 4.85999999999;
long l = (int)Math.round(d * 100); // truncates
d = l / 100.0;
You are returning a double. But double or Double are objects representing a number and don't carry any formatting information. Ìf you need to output two decimal places the point to do this is when you convert your double to a String.
use # if you want to ignore 0
new DecimalFormat("###,#0.00").format(d)
There is another way to achieve this . I have already posted answer in post
will just answer again here. As we will require rounding off values many times .
public class RoundingNumbers {
public static void main(String args[]){
double number = 2.5045;
int decimalsToConsider = 2;
BigDecimal bigDecimal = new BigDecimal(number);
BigDecimal roundedWithScale = bigDecimal.setScale(decimalsToConsider, BigDecimal.ROUND_HALF_UP);
System.out.println("Rounded value with setting scale = "+roundedWithScale);
bigDecimal = new BigDecimal(number);
BigDecimal roundedValueWithDivideLogic = bigDecimal.divide(BigDecimal.ONE,decimalsToConsider,BigDecimal.ROUND_HALF_UP);
System.out.println("Rounded value with Dividing by one = "+roundedValueWithDivideLogic);
}
}
Output we will get is
Rounded value with setting scale = 2.50
Rounded value with Dividing by one = 2.50
double kilobytes = 1205.6358;
double newKB = Math.round(kilobytes*100.0)/100.0;
DecimalFormat df = new DecimalFormat("###.##");
System.out.println("kilobytes (DecimalFormat) : " + df.format(kilobytes));
Try this if u are still getting the above problem
This question already has answers here:
How to round a number to n decimal places in Java
(39 answers)
Closed 7 years ago.
I have read a lot of stackoverflow questions but none seems to be working for me. i am using math.round() to round off.
this is the code:
class round{
public static void main(String args[]){
double a = 123.13698;
double roundOff = Math.round(a*100)/100;
System.out.println(roundOff);
}
}
the output i get is: 123 but i want it to be 123.14. i read that adding *100/100 will help but as you can see i didn't manage to get it to work.
it is absolutely essential for both input and output to be a double.
it would be great great help if you change the line 4 of the code above and post it.
Well this one works...
double roundOff = Math.round(a * 100.0) / 100.0;
Output is
123.14
Or as #Rufein said
double roundOff = (double) Math.round(a * 100) / 100;
this will do it for you as well.
double d = 2.34568;
DecimalFormat f = new DecimalFormat("##.00");
System.out.println(f.format(d));
String roundOffTo2DecPlaces(float val)
{
return String.format("%.2f", val);
}
BigDecimal a = new BigDecimal("123.13698");
BigDecimal roundOff = a.setScale(2, BigDecimal.ROUND_HALF_EVEN);
System.out.println(roundOff);
Go back to your code, and replace 100 by 100.00 and let me know if it works.
However, if you want to be formal, try this:
import java.text.DecimalFormat;
DecimalFormat df=new DecimalFormat("0.00");
String formate = df.format(value);
double finalValue = (Double)df.parse(formate) ;
double roundOff = Math.round(a*100)/100;
should be
double roundOff = Math.round(a*100)/100D;
Adding 'D' to 100 makes it Double literal, thus result produced will have precision
I know this is 2 year old question but as every body faces a problem to round off the values at some point of time.I would like to share a different way which can give us rounded values to any scale by using BigDecimal class .Here we can avoid extra steps which are required to get the final value if we use DecimalFormat("0.00") or using Math.round(a * 100) / 100 .
import java.math.BigDecimal;
public class RoundingNumbers {
public static void main(String args[]){
double number = 123.13698;
int decimalsToConsider = 2;
BigDecimal bigDecimal = new BigDecimal(number);
BigDecimal roundedWithScale = bigDecimal.setScale(2, BigDecimal.ROUND_HALF_UP);
System.out.println("Rounded value with setting scale = "+roundedWithScale);
bigDecimal = new BigDecimal(number);
BigDecimal roundedValueWithDivideLogic = bigDecimal.divide(BigDecimal.ONE,decimalsToConsider,BigDecimal.ROUND_HALF_UP);
System.out.println("Rounded value with Dividing by one = "+roundedValueWithDivideLogic);
}
}
This program would give us below output
Rounded value with setting scale = 123.14
Rounded value with Dividing by one = 123.14
Try :
class round{
public static void main(String args[]){
double a = 123.13698;
double roundOff = Math.round(a*100)/100;
String.format("%.3f", roundOff); //%.3f defines decimal precision you want
System.out.println(roundOff); }}
This is long one but a full proof solution, never fails
Just pass your number to this function as a double, it will return you rounding the decimal value up to the nearest value of 5;
if 4.25, Output 4.25
if 4.20, Output 4.20
if 4.24, Output 4.20
if 4.26, Output 4.30
if you want to round upto 2 decimal places,then use
DecimalFormat df = new DecimalFormat("#.##");
roundToMultipleOfFive(Double.valueOf(df.format(number)));
if up to 3 places, new DecimalFormat("#.###")
if up to n places, new DecimalFormat("#.nTimes #")
public double roundToMultipleOfFive(double x)
{
x=input.nextDouble();
String str=String.valueOf(x);
int pos=0;
for(int i=0;i<str.length();i++)
{
if(str.charAt(i)=='.')
{
pos=i;
break;
}
}
int after=Integer.parseInt(str.substring(pos+1,str.length()));
int Q=after/5;
int R =after%5;
if((Q%2)==0)
{
after=after-R;
}
else
{
if(5-R==5)
{
after=after;
}
else after=after+(5-R);
}
return Double.parseDouble(str.substring(0,pos+1).concat(String.valueOf(after))));
}
seems like you are hit by integer arithmetic: in some languages (int)/(int) will always be evaluated as integer arithmetic.
in order to force floating-point arithmetic, make sure that at least one of the operands is non-integer:
double roundOff = Math.round(a*100)/100.f;
I just modified your code. It works fine in my system. See if this helps
class round{
public static void main(String args[]){
double a = 123.13698;
double roundOff = Math.round(a*100)/100.00;
System.out.println(roundOff);
}
}
public static float roundFloat(float in) {
return ((int)((in*100f)+0.5f))/100f;
}
Should be ok for most cases. You can still changes types if you want to be compliant with doubles for instance.
This question already has answers here:
How to round a number to n decimal places in Java
(39 answers)
Closed 3 years ago.
This is what I did to round a double to 2 decimal places:
amount = roundTwoDecimals(amount);
public double roundTwoDecimals(double d) {
DecimalFormat twoDForm = new DecimalFormat("#.##");
return Double.valueOf(twoDForm.format(d));
}
This works great if the amount = 25.3569 or something like that, but if the amount = 25.00 or the amount = 25.0, then I get 25.0! What I want is both rounding as well as formatting to 2 decimal places.
Just use: (easy as pie)
double number = 651.5176515121351;
number = Math.round(number * 100);
number = number/100;
The output will be 651.52
Are you working with money? Creating a String and then converting it back is pretty loopy.
Use BigDecimal. This has been discussed quite extensively. You should have a Money class and the amount should be a BigDecimal.
Even if you're not working with money, consider BigDecimal.
Use a digit place holder (0), as with '#' trailing/leading zeros show as absent:
DecimalFormat twoDForm = new DecimalFormat("#.00");
Use this
String.format("%.2f", doubleValue) // change 2, according to your requirement.
You can't 'round a double to [any number of] decimal places', because doubles don't have decimal places. You can convert a double to a base-10 String with N decimal places, because base-10 does have decimal places, but when you convert it back you are back in double-land, with binary fractional places.
This is the simplest i could make it but it gets the job done a lot easier than most examples ive seen.
double total = 1.4563;
total = Math.round(total * 100);
System.out.println(total / 100);
The result is 1.46.
You can use org.apache.commons.math.util.MathUtils from apache common
double round = MathUtils.round(double1, 2, BigDecimal.ROUND_HALF_DOWN);
double amount = 25.00;
NumberFormat formatter = new DecimalFormat("#0.00");
System.out.println(formatter.format(amount));
You can use Apache Commons Math:
Precision.round(double x, int scale)
source: http://commons.apache.org/proper/commons-math/apidocs/org/apache/commons/math3/util/Precision.html#round(double,%20int)
Your Money class could be represented as a subclass of Long or having a member representing the money value as a native long. Then when assigning values to your money instantiations, you will always be storing values that are actually REAL money values. You simply output your Money object (via your Money's overridden toString() method) with the appropriate formatting. e.g $1.25 in a Money object's internal representation is 125. You represent the money as cents, or pence or whatever the minimum denomination in the currency you are sealing with is ... then format it on output. No you can NEVER store an 'illegal' money value, like say $1.257.
Starting java 1.8 you can do more with lambda expressions & checks for null. Also, one below can handle Float or Double & variable number of decimal points (including 2 :-)).
public static Double round(Number src, int decimalPlaces) {
return Optional.ofNullable(src)
.map(Number::doubleValue)
.map(BigDecimal::new)
.map(dbl -> dbl.setScale(decimalPlaces, BigDecimal.ROUND_HALF_UP))
.map(BigDecimal::doubleValue)
.orElse(null);
}
You can try this one:
public static String getRoundedValue(Double value, String format) {
DecimalFormat df;
if(format == null)
df = new DecimalFormat("#.00");
else
df = new DecimalFormat(format);
return df.format(value);
}
or
public static double roundDoubleValue(double value, int places) {
if (places < 0) throw new IllegalArgumentException();
long factor = (long) Math.pow(10, places);
value = value * factor;
long tmp = Math.round(value);
return (double) tmp / factor;
}
DecimalFormat df = new DecimalFormat("###.##");
double total = Double.valueOf(val);
First declare a object of DecimalFormat class. Note the argument inside the DecimalFormat is #.00 which means exactly 2 decimal places of rounding off.
private static DecimalFormat df2 = new DecimalFormat("#.00");
Now, apply the format to your double value:
double input = 32.123456;
System.out.println("double : " + df2.format(input)); // Output: 32.12
Note in case of double input = 32.1;
Then the output would be 32.10 and so on.
If you want the result to two decimal places you can do
// assuming you want to round to Infinity.
double tip = (long) (amount * percent + 0.5) / 100.0;
This result is not precise but Double.toString(double) will correct for this and print one to two decimal places. However as soon as you perform another calculation, you can get a result which will not be implicitly rounded. ;)
Math.round is one answer,
public class Util {
public static Double formatDouble(Double valueToFormat) {
long rounded = Math.round(valueToFormat*100);
return rounded/100.0;
}
}
Test in Spock,Groovy
void "test double format"(){
given:
Double performance = 0.6666666666666666
when:
Double formattedPerformance = Util.formatDouble(performance)
println "######################## formatted ######################### => ${formattedPerformance}"
then:
0.67 == formattedPerformance
}
Presuming the amount could be positive as well as negative, rounding to two decimal places may use the following piece of code snippet.
amount = roundTwoDecimals(amount);
public double roundTwoDecimals(double d) {
if (d < 0)
d -= 0.005;
else if (d > 0)
d += 0.005;
return (double)((long)(d * 100.0))/100);
}
where num is the double number
Integer 2 denotes the number of decimal places that we want to print.
Here we are taking 2 decimal palces
System.out.printf("%.2f",num);
Here is an easy way that guarantee to output the myFixedNumber rounded to two decimal places:
import java.text.DecimalFormat;
public class TwoDecimalPlaces {
static double myFixedNumber = 98765.4321;
public static void main(String[] args) {
System.out.println(new DecimalFormat("0.00").format(myFixedNumber));
}
}
The result is: 98765.43
int i = 180;
int j = 1;
double div= ((double)(j*100)/i);
DecimalFormat df = new DecimalFormat("#.00"); // simple way to format till any deciaml points
System.out.println(div);
System.out.println(df.format(div));
You can use this function.
import org.apache.commons.lang.StringUtils;
public static double roundToDecimals(double number, int c)
{
String rightPad = StringUtils.rightPad("1", c+1, "0");
int decimalPoint = Integer.parseInt(rightPad);
number = Math.round(number * decimalPoint);
return number/decimalPoint;
}