Average of 3 numbers (included number rounding)

Average of 3 numbers (included number rounding)

This Java code example demonstrates how to calculate the average of three numbers and round the result to a specified number of decimal places. The script includes a method for rounding double values and uses basic arithmetic operations to compute the average. It then prints the average along with its rounded values in different formats.

Code Example

class AvgNumbers {
	private static double roundDouble(double value, int decimalPoints) {
		double d = Math.pow(10, decimalPoints);
		return Math.round(value * d) / d;
	}

	public static void main(String[] args) {
		// declare variables
		double a, b, c, avg;

		// initialize variables
		a = 11.54;
		b = 7.73;
		c = 10.54;
		
		avg = (a + b + c) / 3;

		System.out.println("Average of " + a + ", " + b + " and " + c + " is: " + avg);
		System.out.println("Rounded value:\n"
							+ String.format("%1.2f", avg) + "\n"
							+ Math.round(avg) + "\n"
							+ roundDouble(avg, 2) + "\n");
	}
}

Code Explanation

Method to Round Double Values

private static double roundDouble(double value, int decimalPoints)

This method rounds a given double value to a specified number of decimal places.

private static double roundDouble(double value, int decimalPoints) {
	double d = Math.pow(10, decimalPoints);
	return Math.round(value * d) / d;
}
  • Parameters:
    • value: The double value to be rounded.
    • decimalPoints: The number of decimal places to round to.
  • Rounding Logic: The method multiplies the value by 10 raised to the power of decimalPoints, rounds the result, and then divides by the same power of 10 to get the rounded value.

Main Method

public static void main(String[] args)

The main method executes the program.

public static void main(String[] args) {
	// declare variables
	double a, b, c, avg;

	// initialize variables
	a = 11.54;
	b = 7.73;
	c = 10.54;
	
	avg = (a + b + c) / 3;

	System.out.println("Average of " + a + ", " + b + " and " + c + " is: " + avg);
	System.out.println("Rounded value:\n"
						+ String.format("%1.2f", avg) + "\n"
						+ Math.round(avg) + "\n"
						+ roundDouble(avg, 2) + "\n");
}
  • Variable Declaration:
    • double a, b, c, avg; declares the variables to hold the three numbers and their average.
  • Variable Initialization:
    • a = 11.54;, b = 7.73;, c = 10.54; initialize the variables with specified values.
  • Average Calculation:
    • avg = (a + b + c) / 3; calculates the average of the three numbers.
  • Output Statements:
    • System.out.println("Average of " + a + ", " + b + " and " + c + " is: " + avg); prints the calculated average.
    • System.out.println("Rounded value:\n" + String.format("%1.2f", avg) + "\n" + Math.round(avg) + "\n" + roundDouble(avg, 2) + "\n"); prints the average in three different rounded formats:
      • String.format("%1.2f", avg) rounds the average to 2 decimal places using String.format.
      • Math.round(avg) rounds the average to the nearest whole number using Math.round.
      • roundDouble(avg, 2) uses the custom roundDouble method to round the average to 2 decimal places.