BigInteger testBit() Method in Java (original) (raw)

Last Updated : 11 Jul, 2025

prerequisite : BigInteger BasicsThe 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);
}

}

`

Output:

The bit at index 3 of 2300 is set = true

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