Dark Mode On/Off

# Java Integer bitCount() Method

Java `bitCount()` method belongs to the `Integer` class. This method is used to return a one-bit number into two's complement binary form of the specified integer value and counts a number of set bits in a binary sequence.

This method takes an integer as a parameter and returns an integer too. For example, if the given input is 1000111110 than this method should return 6, as there are 6 set bits(1) in this input.

### Syntax:

``public static int bitCount(int i)``

### Parameters:

The only parameter that is passed is the integer, of which two's complement binary form will be returned.

### Returns:

This method returns the one-bit number into two's complement binary form of the integer number, hence its return type is also `int.`

## Example 1:

Here, we are entering an integer number 365. The `Integer.toBinaryString()` method will convert the number into its equivalent binary string (101101101 for the integer 365). Then the converted binary number is passed through `Integer.countBit()` to count the number of bits.

``````import java.lang.Integer;

public class StudyTonight {
public static void main(String[] args) {
int i = 365;
int j = -365;
System.out.println("Actual Number is " + i);

// converting the number to its equivalent binary form with base 2
System.out.println("Binary conversion of" + i + " = " + Integer.toBinaryString(i));

//returning the number of one-bits
System.out.println("Number of one bits = " + Integer.bitCount(i));
System.out.println("*******************");
System.out.println("Actual Number is " + j);
System.out.println("Binary conversion of" + j + " = " + Integer.toBinaryString(j));
System.out.println("Number of one bits = " + Integer.bitCount(j));
}
}``````

Actual Number is 365
Binary conversion of365 = 101101101
Number of one bits = 6
*******************
Actual Number is -365
Binary conversion of-365 = 11111111111111111111111010010011
Number of one bits = 27

## Example 2:

Here, we are taking an array of integers. The `Integer.toBinaryString()` method will convert the numbers in the array into its equivalent binary String. The binary string needs to be converted into Integer before passing it through the `countBit()` method, This is done through `Integer.parseInt()` method Then the converted binary number is passed through `Integer.countBit()` to count the number of bits.

``````import java.lang.Integer;

public class StudyTonight {
public static void main(String args[]) {
int[] set = {
72,
78,
56,
89,
80,
66
};
try {
for (int i = 0; i < 6; i++) {
String b = Integer.toBinaryString(set[i]); //Converting the actual number to binary String
int c = Integer.parseInt(b, 2); //Converting the binary String to binary integer of base 2
int d = Integer.bitCount(c); //Counting the set bits
System.out.println("Actual number is " + set[i] + " binary sequence : " + b + ",number of set bits are : " + d);
}
}
catch(Exception e) {
System.out.println("Exception occurred..");
}
}
}``````

Actual number is 72 binary sequence : 1001000,number of set bits are : 2
Actual number is 78 binary sequence : 1001110,number of set bits are : 4
Actual number is 56 binary sequence : 111000,number of set bits are : 3
Actual number is 89 binary sequence : 1011001,number of set bits are : 4
Actual number is 80 binary sequence : 1010000,number of set bits are : 2
Actual number is 66 binary sequence : 1000010,number of set bits are : 2

## Example 3:

Here is a general example where the user can enter the number of his choice and get the desired output. The `try` and `catch` block is used for handling any exception taking place during the execution of the program. (For example, the user enters a String, etc. in place of the integer).

``````import java.lang.Integer;
import java.util. * ;

public class StudyTonight {

public static void main(String[] args) {

System.out.println("Enter number");
Scanner sc = new Scanner(System. in );
try {
int i = sc.nextInt();
System.out.println("Actual Number is " + i);

// converting the number to its equivalent binary form with base 2
System.out.println("Binary conversion of" + i + " = " + Integer.toBinaryString(i));

//returning the number of one-bits
System.out.println("Number of one bits = " + Integer.bitCount(i));
}
catch(Exception e) {
System.out.println("Error!!");
}
}
}``````

Enter number
67
Actual Number is 67
Binary conversion of 67 = 1000011
Number of one bits = 3
**************************************
Enter number
0x896
Error!!

## Live Example:

Here, you can test the live code example. You can execute the example for different values, even can edit and write your examples to test the Java code.