# 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.

 `// 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
```

My Personal Notes arrow_drop_up I am a Developer I love to code and bring my ideas alive

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.

Article Tags :
Practice Tags :

1

Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.