BigInteger testBit() Method in Java

prerequisite : BigInteger Basics The java.math.BigInteger.testBit(index) method returns true if and only if the designated bit is set. This method Computes (this & (1<<n)) != 0). Syntax:

public boolean testBit(int n)

Parameter: The method takes one parameter n of integer type which refers to the index of the bit that needs to be tested. Return Value: The method returns true if and only if the designated bit is set else it will return false. Exception: The method will throw an ArithmeticException when n is negative. Examples:

Input: BigInteger = 2300, n = 4
Output: true
Explanation:
Binary Representation of 2300 = 100011111100
bit at index 4 is 1 so set it means bit is set
so method will return true

Input: BigInteger = 5482549 , n = 1
Output: false

Below program illustrates the testBit() method of BigInteger. Java

// Program to demonstrate the testBit()
// method of BigInteger

import java.math.*;

public class GFG {

    public static void main(String[] args)
    {
        // Creating a BigInteger object
        BigInteger biginteger = new BigInteger("2300");

        // Creating an int i for index
        int i = 3;

        boolean flag = biginteger.testBit(i);

        String result = "The bit at index " + i + " of " + 
        biginteger + " is set = " + flag;

        // Displaying the result
        System.out.println(result);
    }
}

Reference: https://docs.oracle.com/javase/7/docs/api/java/math/BigInteger.html#testBit(int)