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.
// 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)
