DecimalToOctal.java

package com.thealgorithms.conversions;

/**
 * This class converts Decimal numbers to Octal Numbers
 */
public final class DecimalToOctal {
 private static final int OCTAL_BASE = 8;
 private static final int INITIAL_OCTAL_VALUE = 0;
 private static final int INITIAL_PLACE_VALUE = 1;

 private DecimalToOctal() {
 }

 /**
 * Converts a decimal number to its octal equivalent.
 *
 * @param decimal The decimal number to convert.
 * @return The octal equivalent as an integer.
 * @throws IllegalArgumentException if the decimal number is negative.
 */
 public static int convertToOctal(int decimal) {
 if (decimal < 0) {
 throw new IllegalArgumentException("Decimal number cannot be negative.");
 }

 int octal = INITIAL_OCTAL_VALUE;
 int placeValue = INITIAL_PLACE_VALUE;

 while (decimal != 0) {
 int remainder = decimal % OCTAL_BASE;
 octal += remainder * placeValue;
 decimal /= OCTAL_BASE;
 placeValue *= 10;
 }

 return octal;
 }
}