How do you check if a number is 4 digit or not in Java?

“java check if number has 4 digits” Code Answer’s

1. Scanner s = new Scanner(System. in);
2. int n = s. nextInt();
3. int length = String. valueOf(n). length();
4. System. out. print(length);

How do you make a number happy in Java?

Algorithm to Find Happy Numbers in Java Step 1: To Enter a non-zero, positive number from the keyboard and assign it to the variable is called number. Step 2: To calculate the remainder by dividing (\%) the given number with 10. Step 3: Calculate the square of the remaining value and add it to a variable sum.

What is unhappy number in Java?

Java Numbers: Exercise-10 with Solution An unhappy number is a number that is not happy. The first few unhappy numbers are 2, 3, 4, 5, 6, 8, 9, 11, 12, 14, 15, 16, 17, 18, 20.

Why 7 is a happy number?

Iterating this sum-of-squared-digits map always eventually reaches one of the 10 numbers 0, 1, 4, 16, 20, 37, 42, 58, 89, or 145 (OEIS A039943; Porges 1945). For example, starting with 7 gives the sequence 7, 49, 97, 130, 10, 1, so 7 is a happy number.

How do you check if a number contains a digit Java?

To find whether a given string contains a number, convert it to a character array and find whether each character in the array is a digit using the isDigit() method of the Character class.

How do you input a 4 digit number in Java?

1. import java.util.Scanner;
2. class example.
3. {
4. public static void main(String args[])
5. {
6. Scanner in=new Scanner(System.in);
7. System.out.println(“Enter any number : “);
8. String number=in.next();

How do you check if a number is a happy number?

To find whether a given number is happy or not, calculate the square of each digit present in number and add it to a variable sum. If resulting sum is equal to 1 then, given number is a happy number.

How do you check whether a number is happy or not?

What is sunny number?

A number is called a sunny number if the number next to the given number is a perfect square. In other words, a number N will be a sunny number if N+1 is a perfect square.

What is a magic number in Java?

In programming, a magic number is a numeric value that is used directly in the code. It is used for identification purposes.

How do you see if a number contains a digit?

Write a function named containsDigit that determines if a number contains a particular digit. The header should look like: bool containsDigit(int number, int digit); If number contains digit, then the function should return true .