Java Program to Find the Closest Number to a Given Number

Leave a Comment

Learn how to find the closest number to a given number in Java using arrays, loops, and Math.abs().in this program calculates the absolute difference between each array element and the target value using the Math.abs() method.

Code Explanation (Step-by-Step)

  • Create a nearestNumber() method that accepts an integer array and a target value as input.
  • Initialize the index variable with 0. It stores the index of the nearest number found in the array.
  • Use the Math.abs() method to calculate the absolute difference between the first array element and the target value. Store the result in the distance variable.
  • Use a for loop to iterate through the remaining array elements, starting from index 1.
  • Inside the loop, use Math.abs() to calculate the absolute difference between the current array element, arr[i], and the target value. Store the result in the currentDistance variable.
  • If currentDistance is less than distance, assign currentDistance to distance and assign the current index i to index.
  • After completing the loop, return arr[index], which is the number nearest to the target value.
  • Call the nearestNumber() method from the main() method and print the returned value.
				
					public class FindNearestNumber {

    public static int nearestNumber(int[] arr, int target) {
        int index = 0;
        int distance = Math.abs(arr[0] - target);

        for (int i = 1; i < arr.length; i++) {
            int currentDistance = Math.abs(arr[i] - target);

            if (currentDistance < distance) {
                index = i;
                distance = currentDistance;
            }
        }

        return arr[index];
    }

    public static void main(String[] args) {
        int[] arr = {2, 5, 6, 7, 8, 8, 9};
        int target = 11;

        System.out.println("Nearest Number is: " + nearestNumber(arr, target));
    }
}

Output :-
Nearest Number is: 9

What Is the Nearest Number Problem in Java 8

we can sort the array based on the distance from the target and return the first element.

				
					import java.util.Arrays;

public class FindNearestNumber {

    public static int nearestNumber(int[] arr, int target) {
        return Arrays.stream(arr)
                .boxed()
                .min((a, b) -> Integer.compare(
                        Math.abs(a - target),
                        Math.abs(b - target)))
                .orElse(-1);
    }

    public static void main(String[] args) {
        int[] arr = {2, 5, 6, 7, 8, 8, 9};
        int target = 11;

        System.out.println("Nearest Number is: " + nearestNumber(arr, target));
    }
}

Output :-
Nearest Number is: 9

Here are some Java-related programs that will help you understand Java concepts better:   

Related Posts