Java.math.BigInteger.bitLength() Method

Description

The java.math.BigInteger.bitLength() returns the number of bits in the minimal two's-complement representation of this BigInteger, excluding a sign bit. For positive BigIntegers, this is equivalent to the number of bits in the ordinary binary representation. It computes (ceil(log2(this < 0 ? -this : this+1))).

Declaration

Following is the declaration for java.math.BigInteger.bitLength() method.

public int bitLength()

Parameters

NA

Return Value

This method returns number of bits in the minimal two's-complement representation of this BigInteger, excluding a sign bit.

Exception

NA

Example

The following example shows the usage of math.BigInteger.bitLength() method.

package com.tutorialspoint;

import java.math.*;

public class BigIntegerDemo {

   public static void main(String[] args) {

      // create 2 BigInteger objects
      BigInteger bi1, bi2;  

      // create 2 int objects
      int i1, i2;
	
      // assign values to bi1, bi2
      bi1 = new BigInteger("7"); 
      bi2 = new BigInteger("-7"); 

      // perform bitlength operation on bi1, bi2
      i1 = bi1.bitLength();
      i2 = bi2.bitLength();
	  
      String str1 = "Result of bitlength operation on " + bi1 +" is " +i1;
      String str2 = "Result of bitlength operation on " + bi2 +" is " +i2;

      // print i1, i2 values
      System.out.println( str1 );
      System.out.println( str2 );
   }
}

Let us compile and run the above program, this will produce the following result −

Result of bitlength operation on 7 is 3
Result of bitlength operation on -7 is 3