DEV Community

Janardhan Pulivarthi
Janardhan Pulivarthi

Posted on • Edited on

Day 13 of 100 - Java: Basic programs

11:00 PM, I started a 25 min timer. Lazily started reading some basic Java examples.

Create an Immutable class

final class Immutable { private String name; private String number; ... }
Enter fullscreen mode Exit fullscreen mode

ASCII value of a character

char ch = 'b'; int ascii = ch;
Enter fullscreen mode Exit fullscreen mode

Number is odd or even

if (num % 2 == 0) //even else // odd
Enter fullscreen mode Exit fullscreen mode

Factorial of a number

int number = 10; long factorial = 1; for (int i = 1; i <= num; ++i) { factorial *= i; }
Enter fullscreen mode Exit fullscreen mode

Display alphabets

char c; for (c = 'A'; c <= 'Z'; ++c) System.out.print(c + " ");
Enter fullscreen mode Exit fullscreen mode

Check for prime numbers

int number = 29; boolean flag = false; for (int i = 2; i <= number / 2; ++i) { if (num % i == 0) { flag = true; break; } }
Enter fullscreen mode Exit fullscreen mode

GCD using recursion

public static void main(String[] args) { int num1 = 366, num2 = 60; int hcf = hcf(num1, num2); } public static int hcf (int num1, int num2) { if (num2 != 0) return hcf(num2, num1 % num2); else return num1; }
Enter fullscreen mode Exit fullscreen mode

Write a number as sum of two primes

int number = 34; boolean flag = false; for (int i = 2; i <= number / 2; ++i) { if (checkPrime(i)) { if (checkPrime(number -i)) { flag = true; } } } static boolean checkPrime(int number) { boolean isPrime = true; for (int i = 2; i <= number / 2; ++i) { if (num % i == 0) { isprime = false; break; } } return isPrime; }
Enter fullscreen mode Exit fullscreen mode

Top comments (0)