Round/Format Numbers in Java

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System.out.printf¶

System.out.printf("Pi: %.2f", 3.1415926)

Pi: 3.14

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String.format¶

String fval = String.format("%1.2f", 3.1415926);
System.out.print(fval);

3.14

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java.text.DecimalFormat¶

import java.text.DecimalFormat;

DecimalFormat dfmat = new DecimalFormat("#.##");
double fval = Double.valueOf(dfmat.format(3.1415926));
System.out.print(fval);

3.14

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Math.round¶

import java.lang.Math;

double fval = Math.round(3.1415926);
System.out.print(fval);

3.0

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import java.lang.Math;

double fval = Math.round(3.1415926 * 100) / 100.0;
System.out.print(fval);

3.14

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org.apache.commons.math3.util.Precision¶

import org.apache.commons.math3.util.Precision;

double fval = Precision.round(3.1415926, 2);
System.out.print(fval);