Java: Check whether a given integer is a power of 4 or not

Last update on February 20 2025 11:44:04 (UTC/GMT +8 hours)

Check Power of 4

Write a Java program to check whether the given integer is a power of 4 or not.

Given num = 64, return true. Given num = 6, return false.

Pictorial Presentation:

Sample Solution:

Java Code:

import java.util.Scanner;

public class Example110 {
    public static void main(String[] arg) {
        int test = 0; // Initialize a variable 'test' to 0
        Scanner in = new Scanner(System.in); // Create a Scanner object for user input

        System.out.print("Input a positive integer: "); // Prompt the user to input a positive integer
        
        int n = in.nextInt(); // Read the user's input as an integer 

        if (n < 1) {
            System.out.print(Boolean.toString(false)); // If n is less than 1, print "false" and set 'test' to 1
            test = 1;
        }

        if ((n & (n - 1)) != 0) {
            System.out.print(Boolean.toString(false)); // If n is not a power of 2, print "false" and set 'test' to 1
            test = 1;
        }

        if (test == 0) {
            System.out.print(Boolean.toString((n & 0x55555555) != 0)); // If 'test' is 0, check if n has odd bits set and print the result
        }

        System.out.print("\n"); // Print a new line
    }	
}

Sample Output:

Input a positive integer: 64                                           
true

Flowchart:

For more Practice: Solve these Related Problems:

• Modify the program to check if the number is a power of 2 instead.
• Write a program to check if a number is a power of 3.
• Modify the program to find the largest power of 4 less than a given number.
• Write a program to return the exponent when a number is a power of 4.

Java Code Editor:

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