How to print a float with 2 decimal places in Java?
Can I do i开发者_运维技巧t 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 integero
: octal integere
: 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);
}
}
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