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Java BigInteger Class | testBit() Method with Example

BigInteger Class testBit() method: Here, we are going to learn about the testBit() method of BigInteger Class with its syntax and example.
Submitted by Preeti Jain, on May 12, 2020

BigInteger Class testBit() method

• testBit() method is available in java.math package.
• testBit() method is used to check whether the testing bit indexed at the given position is set or not in this BigInteger.
• testBit() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
• testBit() method may throw an exception at the time of testing set bit.
  ArithmeticException: This exception may throw when the given parameter holds value less than 0.

Syntax:

    public boolean testBit(int pos);

Parameter(s):

• int pos – represents the position of bit to be tested.

Return value:

The return type of this method is BigInteger, it returns true when the tested bit is set at the given position otherwise it returns false.

Example:

// Java program to demonstrate the example 
// of boolean testBit(int pos) method of BigInteger

import java.math.*;

public class TestBitOfBI {
    public static void main(String args[]) {
        // Initialize a variable str
        String str = "10";

        // Initialize a BigInteger object 
        BigInteger b_int = new BigInteger(str);

        // Display b_int
        System.out.println("b_int: " + b_int);

        // Display Binary representation of  str 
        System.out.println("Binary Representation of 10: 1010 ");

        System.out.println();

        // checks whether the bit is set "1" at the
        // given indices in this BigInteger or not and
        // binary value of 10 is 1010 so it returns 
        // false because the bit is not set at the given
        // indices 0
        boolean status = b_int.testBit(0);
        System.out.println("b_int.testBit(0): " + status);

        // checks whether the bit is set "1" at the
        // given indices in this BigInteger or not and
        // binary value of 10 is 1010 so it returns 
        // true because the bit is set at the given
        // indices 1
        status = b_int.testBit(1);
        System.out.println("b_int.testBit(1): " + status);
    }
}

Output

b_int: 10
Binary Representation of 10: 1010 

b_int.testBit(0): false
b_int.testBit(1): true