Java Exercises: Multiply two specified integers without using the multiply operator

Java Basic: Exercise-168 with Solution

Write a Java program to multiply two given integers without using the multiply operator(*).

Sample Solution:

Java Code:

import java.util.*;
public class Solution {	
  public static int multiply(int n1, int n2) {
    int result = 0;
    boolean negative_num = (n1 < 0 && n2 >= 0) || (n2 < 0 && n1 >= 0);
    boolean positive_num = !negative_num;
    n1 = Math.abs(n1);
    for (int i = 0; i < n1; i++) {
      if (negative_num && n2 > 0 || positive_num && n2 < 0)
        result -= n2;
      else
        result += n2;
    }

    return result;
 }

   public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Input the first number: ");
        int n1 = in.nextInt();
		System.out.print("Input the second number: ");
        int n2 = in.nextInt();
		System.out.println("\nResult: " + multiply(n1,n2));		
		}

}

Sample Output:

Input the first number:  25
Input the second number:  5

Result: 125

Flowchart:

Java Code Editor:

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